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Archive for the ‘Clinical Diagnostics’ Category


Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

A mutated gene called RAS gives rise to a signalling protein Ral which is involved in tumour growth in the bladder. Many researchers tried and failed to target and stop this wayward gene. Signalling proteins such as Ral usually shift between active and inactive states.

 

So, researchers next tried to stop Ral to get into active state. In inacvtive state Ral exposes a pocket which gets closed when active. After five years, the researchers found a small molecule dubbed BQU57 that can wedge itself into the pocket to prevent Ral from closing and becoming active. Now, BQU57 has been licensed for further development.

 

Researchers have a growing genetic data on bladder cancer, some of which threaten to overturn the supposed causes of bladder cancer. Genetics has also allowed bladder cancer to be reclassified from two categories into five distinct subtypes, each with different characteristics and weak spots. All these advances bode well for drug development and for improved diagnosis and prognosis.

 

Among the groups studying the genetics of bladder cancer are two large international teams: Uromol (named for urology and molecular biology), which is based at Aarhus University Hospital in Denmark, and The Cancer Genome Atlas (TCGA), based at institutions in Texas and Boston. Each team tackled a different type of cancer, based on the traditional classification of whether or not a tumour has grown into the muscle wall of the bladder. Uromol worked on the more common, earlier form, non-muscle-invasive bladder cancer, whereas TCGA is looking at muscle-invasive bladder cancer, which has a lower survival rate.

 

The Uromol team sought to identify people whose non-invasive tumours might return after treatment, becoming invasive or even metastatic. Bladder cancer has a high risk of recurrence, so people whose non-invasive cancer has been treated need to be monitored for many years, undergoing cystoscopy every few months. They looked for predictive genetic footprints in the transcriptome of the cancer, which contains all of a cell’s RNA and can tell researchers which genes are turned on or off.

 

They found three subgroups with distinct basal and luminal features, as proposed by other groups, each with different clinical outcomes in early-stage bladder cancer. These features sort bladder cancer into genetic categories that can help predict whether the cancer will return. The researchers also identified mutations that are linked to tumour progression. Mutations in the so-called APOBEC genes, which code for enzymes that modify RNA or DNA molecules. This effect could lead to cancer and cause it to be aggressive.

 

The second major research group, TCGA, led by the National Cancer Institute and the National Human Genome Research Institute, that involves thousands of researchers across USA. The project has already mapped genomic changes in 33 cancer types, including breast, skin and lung cancers. The TCGA researchers, who study muscle-invasive bladder cancer, have looked at tumours that were already identified as fast-growing and invasive.

 

The work by Uromol, TCGA and other labs has provided a clearer view of the genetic landscape of early- and late-stage bladder cancer. There are five subtypes for the muscle-invasive form: luminal, luminal–papillary, luminal–infiltrated, basal–squamous, and neuronal, each of which is genetically distinct and might require different therapeutic approaches.

 

Bladder cancer has the third-highest mutation rate of any cancer, behind only lung cancer and melanoma. The TCGA team has confirmed Uromol research showing that most bladder-cancer mutations occur in the APOBEC genes. It is not yet clear why APOBEC mutations are so common in bladder cancer, but studies of the mutations have yielded one startling implication. The APOBEC enzyme causes mutations early during the development of bladder cancer, and independent of cigarette smoke or other known exposures.

 

The TCGA researchers found a subset of bladder-cancer patients, those with the greatest number of APOBEC mutations, had an extremely high five-year survival rate of about 75%. Other patients with fewer APOBEC mutations fared less well which is pretty surprising.

 

This detailed knowledge of bladder-cancer genetics may help to pinpoint the specific vulnerabilities of cancer cells in different people. Over the past decade, Broad Institute researchers have identified more than 760 genes that cancer needs to grow and survive. Their genetic map might take another ten years to finish, but it will list every genetic vulnerability that can be exploited. The goal of cancer precision medicine is to take the patient’s tumour and decode the genetics, so the clinician can make a decision based on that information.

 

References:

 

https://www.ncbi.nlm.nih.gov/pubmed/29117162

 

https://www.ncbi.nlm.nih.gov/pubmed/27321955

 

https://www.ncbi.nlm.nih.gov/pubmed/28583312

 

https://www.ncbi.nlm.nih.gov/pubmed/24476821

 

https://www.ncbi.nlm.nih.gov/pubmed/28988769

 

https://www.ncbi.nlm.nih.gov/pubmed/28753430

 

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

Anti-Müllerian Hormone (AMH), is secreted by growing follicles that contains the egg or ovum. According to regular practice low AMH and high Follicle Stimulating Hormone (FSH) are generally considered as indicators of diminished egg quantity in a female. But, there are several cases the female conceived absolutely normally without any support even after low AMH was reported.

 

Therefore, a new research published in the Journal of the American Medical Association declares that AMH doesn’t dictate a woman’s reproductive potential. Although AMH testing is one of the most common ways that doctors assess a woman’s fertility. Present research says that all it takes is one egg each cycle and AMH is not a marker of whether a female can or cannot become pregnant. So, for women who haven’t yet tried to get pregnant and who are wondering whether they are fertile, an AMH value isn’t going to be helpful in that context. In addition, AMH is not necessarily a good marker to predict that whether one has to cryopreserve her eggs. So, practically doctors don’t yet have a way to definitively predict egg quality or a woman’s long-term ability to conceive, but age is obviously one of the most important factors.

 

The above mentioned study followed 750 women between the ages of 30 and 44 who had been trying to conceive for three months or less. During the 12-month observation period, those with low AMH values of less than 0.7 were not less likely to conceive than those who had normal AMH values. The study had various limitations, however, that are worth noting. The researchers only included women who did not have a history of infertility. Women who sought fertility treatments (about 6 percent) were withdrawn. And only 12 percent of the women were in the 38-to-44 age range. In addition, the number of live births was unavailable.

 

Among women aged 30 to 44 years without a history of infertility who had been trying to conceive for 3 months or less, biomarkers indicating diminished ovarian reserve compared with normal ovarian reserve were not associated with reduced fertility. These findings do not support the use of urinary or blood FSH tests or AMH levels to assess natural fertility for women with these characteristics. The researchers’ next want to see whether low AMH is associated with a higher risk of miscarriage among the women who conceived.

 

Although AMH testing isn’t designed to be an overall gauge of a woman’s fertility, it can still provide valuable information, especially for women who are infertile and seeking treatment. It can assist in diagnosing polycystic ovarian syndrome, and identify when a woman is getting closer to menopause. Previous research also showed that AMH is good predictor of a woman’s response to ovarian stimulation for in vitro fertilization and therefore it can predict the probability of conceiving via in vitro fertilization (I.V.F.).

 

References:

 

https://jamanetwork.com/journals/jama/article-abstract/2656811?JamaNetworkReader=True

 

https://www.nytimes.com/2017/10/16/health/fertility-test-ovarian-reserve.html

 

https://academic.oup.com/humrep/article/26/11/2925/656065

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3339896/

 

https://www.ncbi.nlm.nih.gov/pubmed/27179263

 

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Trends in Sperm Count

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

There has been a genuine decline in semen quality over the past 50 years. There is lot of controversy about this as there are limitations in studies that have attempted to address it. Sperm count is of considerable public health importance for several reasons. First, sperm count is closely linked to male fecundity and is a crucial component of semen analysis, the first step to identify male factor infertility.

Reduced sperm count is associated with cryptorchidism, hypospadias and testicular cancer. It may be associated with multiple environmental influences, including endocrine disrupting chemicals, pesticides, heat and lifestyle factors, including diet, stress, smoking and BMI. Therefore, sperm count may sensitively reflect the impacts of the modern environment on male health throughout the life span.

This study provided a systematic review and meta-regression analysis of recent trends in sperm counts as measured by sperm concentration (SC) and total sperm count (TSC), and their modification by fertility and geographic group. Analyzing trends by birth cohorts instead of year of sample collection may aid in assessing the causes of the decline (prenatal or in adult life) but was not feasible owing to lack of information.

This rigorous and comprehensive analysis found that SC declined 52.4% between 1973 and 2011 among unselected men from western countries, with no evidence of a ‘leveling off’ in recent years. Declining mean SC implies that an increasing proportion of men have sperm counts below any given threshold for sub-fertility or infertility. The high proportion of men from western countries with concentration below 40 million/ml is particularly concerning given the evidence that SC below this threshold is associated with a decreased monthly probability of conception.

Declines in sperm count have implications beyond fertility and reproduction. The decline reported in this study is consistent with reported trends in other male reproductive health indicators, such as testicular germ cell tumors, cryptorchidism, onset of male puberty and total testosterone levels. The public health implications are even wider. Recent studies have shown that poor sperm count is associated with overall morbidity and mortality. While the current study is not designed to provide direct information on the causes of the observed declines, sperm count has been plausibly associated with multiple environmental and lifestyle influences, both prenatally and in adult life. In particular, endocrine disruption from chemical exposures or maternal smoking during critical windows of male reproductive development may play a role in prenatal life, while lifestyle changes and exposure to pesticides may play a role in adult life.

These findings strongly suggest a significant decline in male reproductive health, which has serious implications beyond fertility concerns. Research on causes and implications of this decline is urgently needed.

 

REFERENCES

Temporal trends in sperm count: a systematic review and meta-regression analysis 

Hagai Levine, Niels Jørgensen, Anderson Martino‐Andrade, Jaime Mendiola, Dan Weksler-Derri, Irina Mindlis, Rachel Pinotti, Shanna H Swan. Human Reproduction Update, July 25, 2017, doi:10.1093/humupd/dmx022.

Link: https://academic.oup.com/humupd/article-lookup/doi/10.1093/humupd/dmx022.

Sperm Counts Are Declining Among Western Men – Interview with Dr. Hagai Levine

https://news.afhu.org/news/sperm-counts-are-declining-among-western-men?utm_source=Master+List&utm_campaign=dca529d919-EMAIL_CAMPAIGN_2017_07_27&utm_medium=email&utm_term=0_343e19a421-dca529d919-92801633

J Urol. 1983 Sep;130(3):467-75.

A critical method of evaluating tests for male infertility.

https://www.ncbi.nlm.nih.gov/pubmed/6688444

Hum Reprod. 1993 Jan;8(1):65-70.

Estimating fertility potential via semen analysis data.

https://www.ncbi.nlm.nih.gov/pubmed/8458929

Lancet. 1998 Oct 10;352(9135):1172-7.

Relation between semen quality and fertility: a population-based study of 430 first-pregnancy planners.

https://www.ncbi.nlm.nih.gov/pubmed/9777833

Hum Reprod Update. 2010 May-Jun;16(3):231-45. doi: 10.1093/humupd/dmp048. Epub 2009 Nov 24.

World Health Organization reference values for human semen characteristics.

https://www.ncbi.nlm.nih.gov/pubmed/19934213

J Nutr. 2016 May;146(5):1084-92. doi: 10.3945/jn.115.226563. Epub 2016 Apr 13.

Intake of Fruits and Vegetables with Low-to-Moderate Pesticide Residues Is Positively Associated with Semen-Quality Parameters among Young Healthy Men.

https://www.ncbi.nlm.nih.gov/pubmed/27075904

Reprod Toxicol. 2003 Jul-Aug;17(4):451-6.

Semen quality of Indian welders occupationally exposed to nickel and chromium.

https://www.ncbi.nlm.nih.gov/pubmed/12849857

Fertil Steril. 1996 May;65(5):1009-14.

Semen analyses in 1,283 men from the United States over a 25-year period: no decline in quality.

https://www.ncbi.nlm.nih.gov/pubmed/8612826

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First Haploid Human Stem Cells

Reported: Irina Robu, PhD

Most of the cells in our body are diploid, which indicate they carry two sets of chromosomes—one from each parent. So far, scientists have only succeeded in generating haploid embryonic stem cells—which comprise a single set of chromosomes in non-human mammals such as mice, rats and monkeys. Nevertheless, scientists have tried to isolate and duplicate these haploid ESCs in humans, which would allow them to work with one set of human chromosomes as opposed to a mixture from both parents.

Scientists from Hebrew from The Hebrew University of Jerusalem, Columbia University Medical Center (CUMC) and The New York Stem Cell Foundation Research Institute (NYSCF) were successful in generating a new type of embryonic stem cells that has a single copy of the human genome, instead of two copies which is typically found in normal stem cells.

This landmark was finally obtained by Ido Sagi, working as a PhD student at the Hebrew University of Jerusalem which was successful in isolating and maintaining haploid embryonic stem cells in humans. Unlike in mice, these haploid stem cells were capable to differentiate into various cell types such as brain, heart and pancreas, although holding a single set of chromosomes. Sagi and his advisor, Prof. Nissim Benvenisty showed that this new human stem cell type will play an important role in human genetic and medical research.  This new human cell type cell type will aid in understanding human development and it will make genetic screening simpler and more precise, by examining a single set of chromosomes.

Based on this research, the Technology Transfer arm of the Hebrew University, started a new company New Stem, which is developing a diagnostic kit for predicting resistance to chemotherapy treatments. By gathering a broad library of human pluripotent stem cells with various genetic makeups and mutations. The company is planning to use this kit for personalized medication and future therapeutic and reproductive products.

SOURCE

https://medicalxpress.com/news/2017-06-haploid-human-stem-cells-medical.html#jCp

Other related articles published in this Open Access Online Scientific Journal include the following:

Ido Sagi – PhD Student @HUJI, 2017 Kaye Innovation Award winner for leading research that yielded the first successful isolation and maintenance of haploid embryonic stem cells in humans.

Reporter: Aviva Lev-Ari, PhD, RN

Ido Sagi – PhD Student @HUJI, 2017 Kaye Innovation Award winner for leading research that yielded the first successful isolation and maintenance of haploid embryonic stem cells in humans.

 

 

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

During pregnancy, the baby is mostly protected from harmful microorganisms by the amniotic sac, but recent research suggests the baby could be exposed to small quantities of microbes from the placenta, amniotic fluid, umbilical cord blood and fetal membranes. One theory is that any possible prenatal exposure could ‘pre-seed’ the infant microbiome. In other words, to set the right conditions for the ‘main seeding event’ for founding the infant microbiome.

When a mother gives birth vaginally and if she breastfeeds, she passes on colonies of essential microbes to her baby. This continues a chain of maternal heritage that stretches through female ancestry for thousands of generations, if all have been vaginally born and breastfed. This means a child’s microbiome, that is the trillions of microorganisms that live on and in him or her, will resemble the microbiome of his/her mother, the grandmother, the great-grandmother and so on, if all have been vaginally born and breastfed.

As soon as the mother’s waters break, suddenly the baby is exposed to a wave of the mother’s vaginal microbes that wash over the baby in the birth canal. They coat the baby’s skin, and enter the baby’s eyes, ears, nose and some are swallowed to be sent down into the gut. More microbes form of the mother’s gut microbes join the colonization through contact with the mother’s faecal matter. Many more microbes come from every breath, from every touch including skin-to-skin contact with the mother and of course, from breastfeeding.

With formula feeding, the baby won’t receive the 700 species of microbes found in breast milk. Inside breast milk, there are special sugars called human milk oligosaccharides (HMO’s) that are indigestible by the baby. These sugars are designed to feed the mother’s microbes newly arrived in the baby’s gut. By multiplying quickly, the ‘good’ bacteria crowd out any potentially harmful pathogens. These ‘good’ bacteria help train the baby’s naive immune system, teaching it to identify what is to be tolerated and what is pathogen to be attacked. This leads to the optimal training of the infant immune system resulting in a child’s best possible lifelong health.

With C-section birth and formula feeding, the baby is not likely to acquire the full complement of the mother’s vaginal, gut and breast milk microbes. Therefore, the baby’s microbiome is not likely to closely resemble the mother’s microbiome. A baby born by C-section is likely to have a different microbiome from its mother, its grandmother, its great-grandmother and so on. C-section breaks the chain of maternal heritage and this break can never be restored.

The long term effect of an altered microbiome for a child’s lifelong health is still to be proven, but many studies link C-section with a significantly increased risk for developing asthma, Type 1 diabetes, celiac disease and obesity. Scientists might not yet have all the answers, but the picture that is forming is that C-section and formula feeding could be significantly impacting the health of the next generation. Through the transgenerational aspect to birth, it could even be impacting the health of future generations.

References:

https://blogs.scientificamerican.com/guest-blog/shortchanging-a-babys-microbiome/

https://www.ncbi.nlm.nih.gov/pubmed/23926244

https://www.ncbi.nlm.nih.gov/pubmed/26412384

https://www.ncbi.nlm.nih.gov/pubmed/25290507

https://www.ncbi.nlm.nih.gov/pubmed/25974306

https://www.ncbi.nlm.nih.gov/pubmed/24637604

https://www.ncbi.nlm.nih.gov/pubmed/22911969

https://www.ncbi.nlm.nih.gov/pubmed/25650398

https://www.ncbi.nlm.nih.gov/pubmed/27362264

https://www.ncbi.nlm.nih.gov/pubmed/27306663

http://www.mdpi.com/1099-4300/14/11/2036

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4464665/

https://www.ncbi.nlm.nih.gov/pubmed/24848255

https://www.ncbi.nlm.nih.gov/pubmed/26412384

https://www.ncbi.nlm.nih.gov/pubmed/28112736

http://ndnr.com/gastrointestinal/the-infant-microbiome-how-environmental-maternal-factors-influence-its-development/

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3D Liver Model in a Droplet

Curator: Marzan Khan, BSc

Recently, a Harvard University Professor of Physics and Applied Physics, David Weitz and his team of researchers have successfully generated 3D models of liver tissue composed of two different kinds of liver cells, precisely compartmentalized in a core-shell droplet, using the microfluidics approach(1). Compared to alternative in-vitro methods, this approach comes with more advantages – it is cost-effective, can be quickly assembled and produces millions of organ droplets in a second(1). It is the first “organ in a droplet” technology that enables two disparate liver cells to physically co-exist and exchange biochemical information, thus making it a good mimic of the organ in vivo(1).

Liver tissue models are used by researchers to investigate the effect of drugs and other chemical compounds, either alone or in combination on liver toxicity(2). The liver is the primary center of drug metabolism, detoxification and removal and all of these processes need to be carried out systematically in order to maintain a homeostatic environment within the body(2) Any deviation from the steady state will shift the dynamic equilibrium of metabolism, leading to production of reactive oxygen species (ROS)(2). These are harmful because they will exert oxidative stress on the liver, and ultimately cause the organ to malfunction. Drug-induced liver toxicity is a critical problem – 10% of all cases of acute hepatitis, 5% of all hospital admissions, and 50% of all acute liver failures are caused by it(2).

Before any novel drug is launched into the market, it is tested in-vitro, in animal models, and then progresses onto human clinical trials(1). Weitz’s system can produce up to one-thousand organ droplets per second, each of which can be used in an experiment to test for drug toxicity(1). Clarifying further, he asserts that “Each droplet is like a mini experiment. Normally, if we are running experiments, say in test tubes, we need a milliliter of fluid per test tube. If we were to do a million experiments, we would need a thousand liters of fluid. That’s the equivalent of a thousand milk jugs! Here, each droplet is only a nanoliter, so we can do the whole experiment with one milliliter of fluid, meaning we can do a million more experiments with the same amount of fluid.”

Testing hepatocytes alone on a petri dish is a poor indicator of liver-specific functions because the liver is made up of multiple cells systematically arranged on an extracellular matrix and functionally interdependent(3). The primary hepatocytes, hepatic stellate cells, Kupffer cells, endothelial cells and fibroblasts form the basic components of a functioning liver(3). Weitz’s upgraded system contains hepatocytes (that make up the majority of liver cells and carry out most of the important functions) supported by a network of fibroblasts(3). His microfluidic chip is comprised of a network of constricted, circular channels spanning the micrometer range, the inner phase of which contains hepatocytes mixed in a cell culture solution(3). The surrounding middle phase accommodates fibroblasts in an alginate solution and the two liquids remain separated due to differences in their chemical properties as well as the physics of fluids travelling in narrow channels. Addition of a fluorinated carbon oil interferes with the two aqueous layers, forcing them to become individual monodisperse droplets(3). The hydrogel shell is completed when a 0.15% solution of acetic acid facilitates the cross-linking of alginate to form a gelatinous shell, locking the fibroblasts in place(3). Thus, the aqueous core of hepatocytes are encapsulated by fibroblasts confined to a strong hydrogel network, creating a core-shell hydrogel scaffold of 3D liver micro-tissue in a droplet(3). Using empirical analysis, scientists have shown that albumin secretion and urea synthesis (two important markers of liver function) were significantly higher in a co-culture of hepatocytes and fibroblasts 3D core-shell spheroids compared to a monotypic cell-culture of hepatocyte-only spheroids(3). These results validate the theory that homotypic as well as heterotypic communication between cells are important to achieve optimal organ function in vitro(3).

This system of creating micro-tissues in a droplet with enhanced properties is a step-forward in biomedical science(3). It can be used in experiments to test for a myriad of drugs, chemicals and cosmetics on different human tissue samples, as well as to understand the biological connectivity of contrasting cells(3).

diagram

Image source: DOI: 10.1039/c6lc00231

A simple demonstration of the microfluidic chip that combines different solutions to create a core-shell droplet consisting of two different kinds of liver cells.

References:

  1. National Institute of Biomedical Imaging and Bioengineering. (2016, December 13). New device creates 3D livers in a droplet.ScienceDaily. Retrieved February 9, 2017 from https://www.sciencedaily.com/releases/2016/12/161213112337.htm
  2. Singh, D., Cho, W. C., & Upadhyay, G. (2015). Drug-Induced Liver Toxicity and Prevention by Herbal Antioxidants: An Overview.Frontiers in Physiology,6, 363. http://doi.org/10.3389/fphys.2015.00363
  3. Qiushui Chen, Stefanie Utech, Dong Chen, Radivoje Prodanovic, Jin-Ming Lin and David A. Weitz; Controlled assembly of heterotypic cells in a core– shell scaffold: organ in a droplet; Lab Chip, 2016, 16, 1346; DOI: 10.1039/c6lc00231

Other related articles on 3D on a Chip published in this Open Access Online Scientific Journal include the following:

 

What could replace animal testing – ‘Human-on-a-chip’ from Lawrence Livermore National Laboratory

Reporter: Aviva Lev-Ari, PhD, RN

AGENDA for Second Annual Organ-on-a-Chip World Congress & 3D-Culture Conference, July 7-8, 2016, Wyndham Boston Beacon Hill by SELECTBIO US

Reporter: Aviva Lev-Ari, PhD, RN

Medical MEMS, BioMEMS and Sensor Applications

Curator and Reporter: Aviva Lev-Ari, PhD, RN

Contribution to Inflammatory Bowel Disease (IBD) of bacterial overgrowth in gut on a chip

Larry H. Bernstein, MD, FCAP, Curator

Current Advances in Medical Technology

Larry H. Bernstein, MD, FCAP, Curator

 

Other related articles on Liver published in this Open Access Online Scientific Journal include the following:

 

Alnylam down as it halts development for RNAi liver disease candidate

by Stacy Lawrence

LIVE 9/21 8AM to 2:40PM Targeting Cardio-Metabolic Diseases: A focus on Liver Fibrosis and NASH Targets at CHI’s 14th Discovery On Target, 9/19 – 9/22/2016, Westin Boston Waterfront, Boston

Reporter: Aviva Lev-Ari, PhD, RN

2016 Nobel in Economics for Work on The Theory of Contracts to winners: Oliver Hart and Bengt Holmstrom

Reporter: Aviva Lev-Ari, PhD, RN

LIVE 9/20 2PM to 5:30PM New Viruses for Therapeutic Gene Delivery at CHI’s 14th Discovery On Target, 9/19 – 9/22/2016, Westin Boston Waterfront, Boston

Reporter: Aviva Lev-Ari, PhD, RN

Seven Cancers: oropharynx, larynx, oesophagus, liver, colon, rectum and breast are caused by Alcohol Consumption

Reporter: Aviva Lev-Ari, PhD, RN

 

Other related articles on 3D on a Chip published in this Open Access Online Scientific Journal include the following:

 

Liquid Biopsy Chip detects an array of metastatic cancer cell markers in blood – R&D @Worcester Polytechnic Institute,  Micro and Nanotechnology Lab

Reporters: Tilda Barliya, PhD and Aviva Lev-Ari, PhD, RN

Trovagene’s ctDNA Liquid Biopsy urine and blood tests to be used in Monitoring and Early Detection of Pancreatic Cancer

Reporters: David Orchard-Webb, PhD and Aviva Lev-Ari, PhD, RN

Liquid Biopsy Assay May Predict Drug Resistance

Curator: Larry H. Bernstein, MD, FCAP

One blood sample can be tested for a comprehensive array of cancer cell biomarkers: R&D at WPI

Curator: Marzan Khan, B.Sc

Real Time Coverage of the AGENDA for Powering Precision Health (PPH) with Science, 9/26/2016, Cambridge Marriott Hotel, Cambridge, MA

Reporter: Aviva Lev-Ari, PhD, RN

 

 

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

MicroRNAs (miRNAs) are a group of small non-coding RNA molecules that play a major role in posttranscriptional regulation of gene expression and are expressed in an organ-specific manner. One miRNA can potentially regulate the expression of several genes, depending on cell type and differentiation stage. They control every cellular process and their altered regulation is involved in human diseases. miRNAs are differentially expressed in the male and female gonads and have an organ-specific reproductive function. Exerting their affect through germ cells and gonadal somatic cells, miRNAs regulate key proteins necessary for gonad development. The role of miRNAs in the testes is only starting to emerge though they have been shown to be required for adequate spermatogenesis. In the ovary, miRNAs play a fundamental role in follicles’ assembly, growth, differentiation, and ovulation.

 

Deciphering the underlying causes of idiopathic male infertility is one of the main challenges in reproductive medicine. This is especially relevant in infertile patients displaying normal seminal parameters and no urogenital or genetic abnormalities. In these cases, the search for additional sperm biomarkers is of high interest. This study was aimed to determine the implications of the sperm miRNA expression profiles in the reproductive capacity of normozoospermic infertile individuals. The expression levels of 736 miRNAs were evaluated in spermatozoa from normozoospermic infertile males and normozoospermic fertile males analyzed under the same conditions. 57 miRNAs were differentially expressed between populations; 20 of them was regulated by a host gene promoter that in three cases comprised genes involved in fertility. The predicted targets of the differentially expressed miRNAs unveiled a significant enrichment of biological processes related to embryonic morphogenesis and chromatin modification. Normozoospermic infertile individuals exhibit a specific sperm miRNA expression profile clearly differentiated from normozoospermic fertile individuals. This miRNA cargo has potential implications in the individuals’ reproductive competence.

 

Circulating or “extracellular” miRNAs detected in biological fluids, could be used as potential diagnostic and prognostic biomarkers of several disease, such as cancer, gynecological and pregnancy disorders. However, their contributions in female infertility and in vitro fertilization (IVF) remain unknown. Polycystic ovary syndrome (PCOS) is a frequent endocrine disorder in women. PCOS is associated with altered features of androgen metabolism, increased insulin resistance and impaired fertility. Furthermore, PCOS, being a syndrome diagnosis, is heterogeneous and characterized by polycystic ovaries, chronic anovulation and evidence of hyperandrogenism, as well as being associated with chronic low-grade inflammation and an increased life time risk of type 2 diabetes. Altered miRNA levels have been associated with diabetes, insulin resistance, inflammation and various cancers. Studies have shown that circulating miRNAs are present in whole blood, serum, plasma and the follicular fluid of PCOS patients and that these might serve as potential biomarkers and a new approach for the diagnosis of PCOS. Presence of miRNA in mammalian follicular fluid has been demonstrated to be enclosed within microvesicles and exosomes or they can also be associated to protein complexes. The presence of microvesicles and exosomes carrying microRNAs in follicular fluid could represent an alternative mechanism of autocrine and paracrine communication inside the ovarian follicle. The investigation of the expression profiles of five circulating miRNAs (let-7b, miR-29a, miR-30a, miR-140 and miR-320a) in human follicular fluid from women with normal ovarian reserve and with polycystic ovary syndrome (PCOS) and their ability to predict IVF outcomes showed that these miRNAs could provide new helpful biomarkers to facilitate personalized medical care for oocyte quality in ART (Assisted Reproductive Treatment) and during IVF (In Vitro Fertilization).

 

References:

 

http://link.springer.com/chapter/10.1007%2F978-3-319-31973-5_12

 

http://onlinelibrary.wiley.com/doi/10.1111/andr.12276/abstract;jsessionid=F805A89DCC94BDBD42D6D60C40AD4AB0.f03t03

 

http://www.sciencedirect.com/science/article/pii/S0009279716302241

 

http://link.springer.com/article/10.1007%2Fs10815-016-0657-9

 

http://www.nature.com/articles/srep24976

 

 

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