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Lesson 9 Cell Signaling:  Curations and Articles of reference as supplemental information for lecture section on WNTs: #TUBiol3373

Stephen J. Wiilliams, Ph.D: Curator

The following contain curations of scientific articles from the site https://pharmaceuticalintelligence.com  intended as additional reference material  to supplement material presented in the lecture.

Wnts are a family of lipid-modified secreted glycoproteins which are involved in:

Normal physiological processes including

A. Development:

– Osteogenesis and adipogenesis (Loss of wnt/β‐catenin signaling causes cell fate shift of preosteoblasts from osteoblasts to adipocytes)

  – embryogenesis including body axis patterning, cell fate specification, cell proliferation and cell migration

B. tissue regeneration in adult tissue

read: Wnt signaling in the intestinal epithelium: from endoderm to cancer

And in pathologic processes such as oncogenesis (refer to Wnt/β-catenin Signaling [7.10]) and to your Powerpoint presentation

 

The curation Wnt/β-catenin Signaling is a comprehensive review of canonical and noncanonical Wnt signaling pathways

 

To review:

 

 

 

 

 

 

 

 

 

 

 

Activating the canonical Wnt pathway frees B-catenin from the degradation complex, resulting in B-catenin translocating to the nucleus and resultant transcription of B-catenin/TCF/LEF target genes.

Fig. 1 Canonical Wnt/FZD signaling pathway. (A) In the absence of Wnt signaling, soluble β-catenin is phosphorylated by a degradation complex consisting of the kinases GSK3β and CK1α and the scaffolding proteins APC and Axin1. Phosphorylated β-catenin is targeted for proteasomal degradation after ubiquitination by the SCF protein complex. In the nucleus and in the absence of β-catenin, TCF/LEF transcription factor activity is repressed by TLE-1; (B) activation of the canonical Wnt/FZD signaling leads to phosphorylation of Dvl/Dsh, which in turn recruits Axin1 and GSK3β adjacent to the plasma membrane, thus preventing the formation of the degradation complex. As a result, β-catenin accumulates in the cytoplasm and translocates into the nucleus, where it promotes the expression of target genes via interaction with TCF/LEF transcription factors and other proteins such as CBP, Bcl9, and Pygo.

NOTE: In the canonical signaling, the Wnt signal is transmitted via the Frizzled/LRP5/6 activated receptor to INACTIVATE the degradation complex thus allowing free B-catenin to act as the ultimate transducer of the signal.

Remember, as we discussed, the most frequent cancer-related mutations of WNT pathway constituents is in APC.

This shows how important the degradation complex is in controlling canonical WNT signaling.

Other cell signaling systems are controlled by protein degradation:

A.  The Forkhead family of transcription factors

Read: Regulation of FoxO protein stability via ubiquitination and proteasome degradation

B. Tumor necrosis factor α/NF κB signaling

Read: NF-κB, the first quarter-century: remarkable progress and outstanding questions

1.            Question: In cell involving G-proteins, the signal can be terminated by desensitization mechanisms.  How is both the canonical and noncanonical Wnt signal eventually terminated/desensitized?

We also discussed the noncanonical Wnt signaling pathway (independent of B-catenin induced transcriptional activity).  Note that the canonical and noncanonical involve different transducers of the signal.

Noncanonical WNT Signaling

Note: In noncanonical signaling the transducer is a G-protein and second messenger system is IP3/DAG/Ca++ and/or kinases such as MAPK, JNK.

Depending on the different combinations of WNT ligands and the receptors, WNT signaling activates several different intracellular pathways  (i.e. canonical versus noncanonical)

 

In addition different Wnt ligands are expressed at different times (temporally) and different cell types in development and in the process of oncogenesis. 

The following paper on Wnt signaling in ovarian oncogenesis shows how certain Wnt ligands are expressed in normal epithelial cells but the Wnt expression pattern changes upon transformation and ovarian oncogenesis. In addition, differential expression of canonical versus noncanonical WNT ligands occur during the process of oncogenesis (for example below the authors describe the noncanonical WNT5a is expressed in normal ovarian  epithelia yet WNT5a expression in ovarian cancer is lower than the underlying normal epithelium. However the canonical WNT10a, overexpressed in ovarian cancer cells, serves as an oncogene, promoting oncogenesis and tumor growth.

Wnt5a Suppresses Epithelial Ovarian Cancer by Promoting Cellular Senescence

Benjamin G. Bitler,1 Jasmine P. Nicodemus,1 Hua Li,1 Qi Cai,2 Hong Wu,3 Xiang Hua,4 Tianyu Li,5 Michael J. Birrer,6Andrew K. Godwin,7 Paul Cairns,8 and Rugang Zhang1,*

A.           Abstract

Epithelial ovarian cancer (EOC) remains the most lethal gynecological malignancy in the US. Thus, there is an urgent need to develop novel therapeutics for this disease. Cellular senescence is an important tumor suppression mechanism that has recently been suggested as a novel mechanism to target for developing cancer therapeutics. Wnt5a is a non-canonical Wnt ligand that plays a context-dependent role in human cancers. Here, we investigate the role of Wnt5a in regulating senescence of EOC cells. We demonstrate that Wnt5a is expressed at significantly lower levels in human EOC cell lines and in primary human EOCs (n = 130) compared with either normal ovarian surface epithelium (n = 31; p = 0.039) or fallopian tube epithelium (n = 28; p < 0.001). Notably, a lower level of Wnt5a expression correlates with tumor stage (p = 0.003) and predicts shorter overall survival in EOC patients (p = 0.003). Significantly, restoration of Wnt5a expression inhibits the proliferation of human EOC cells both in vitro and in vivo in an orthotopic EOC mouse model. Mechanistically, Wnt5a antagonizes canonical Wnt/β-catenin signaling and induces cellular senescence by activating the histone repressor A (HIRA)/promyelocytic leukemia (PML) senescence pathway. In summary, we show that loss of Wnt5a predicts poor outcome in EOC patients and Wnt5a suppresses the growth of EOC cells by triggering cellular senescence. We suggest that strategies to drive senescence in EOC cells by reconstituting Wnt5a signaling may offer an effective new strategy for EOC therapy.

Oncol Lett. 2017 Dec;14(6):6611-6617. doi: 10.3892/ol.2017.7062. Epub 2017 Sep 26.

Clinical significance and biological role of Wnt10a in ovarian cancer. 

Li P1Liu W1Xu Q1Wang C1.

Ovarian cancer is one of the five most malignant types of cancer in females, and the only currently effective therapy is surgical resection combined with chemotherapy. Wnt family member 10A (Wnt10a) has previously been identified to serve an oncogenic function in several tumor types, and was revealed to have clinical significance in renal cell carcinoma; however, there is still only limited information regarding the function of Wnt10a in the carcinogenesis of ovarian cancer. The present study identified increased expression levels of Wnt10a in two cell lines, SKOV3 and A2780, using reverse transcription-polymerase chain reaction. Functional analysis indicated that the viability rate and migratory ability of SKOV3 cells was significantly inhibited following Wnt10a knockdown using short interfering RNA (siRNA) technology. The viability rate of SKOV3 cells decreased by ~60% compared with the control and the migratory ability was only ~30% of that in the control. Furthermore, the expression levels of β-catenin, transcription factor 4, lymphoid enhancer binding factor 1 and cyclin D1 were significantly downregulated in SKOV3 cells treated with Wnt10a-siRNA3 or LGK-974, a specific inhibitor of the canonical Wnt signaling pathway. However, there were no synergistic effects observed between Wnt10a siRNA3 and LGK-974, which indicated that Wnt10a activated the Wnt/β-catenin signaling pathway in SKOV3 cells. In addition, using quantitative PCR, Wnt10a was overexpressed in the tumor tissue samples obtained from 86 patients with ovarian cancer when compared with matching paratumoral tissues. Clinicopathological association analysis revealed that Wnt10a was significantly associated with high-grade (grade III, P=0.031) and late-stage (T4, P=0.008) ovarian cancer. Furthermore, the estimated 5-year survival rate was 18.4% for patients with low Wnt10a expression levels (n=38), whereas for patients with high Wnt10a expression (n=48) the rate was 6.3%. The results of the present study suggested that Wnt10a serves an oncogenic role during the carcinogenesis and progression of ovarian cancer via the Wnt/β-catenin signaling pathway.

Targeting the Wnt Pathway includes curations of articles related to the clinical development of Wnt signaling inhibitors as a therapeutic target in various cancers including hepatocellular carcinoma, colon, breast and potentially ovarian cancer.

 

2.         Question: Given that different Wnt ligands and receptors activate different signaling pathways, AND  WNT ligands  can be deferentially and temporally expressed  in various tumor types and the process of oncogenesis, how would you approach a personalized therapy targeting the WNT signaling pathway?

3.         Question: What are the potential mechanisms of either intrinsic or acquired resistance to Wnt ligand antagonists being developed?

 

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

Targeting the Wnt Pathway [7.11]

Wnt/β-catenin Signaling [7.10]

Cancer Signaling Pathways and Tumor Progression: Images of Biological Processes in the Voice of a Pathologist Cancer Expert

e-Scientific Publishing: The Competitive Advantage of a Powerhouse for Curation of Scientific Findings and Methodology Development for e-Scientific Publishing – LPBI Group, A Case in Point 

Electronic Scientific AGORA: Comment Exchanges by Global Scientists on Articles published in the Open Access Journal @pharmaceuticalintelligence.com – Four Case Studies

 

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Relations between Breast Cancer and DIET: amino acid called asparagine

Reporter: Aviva Lev-Ari, PhD, RN

 

 

Diet may influence the spread of a deadly type of breast cancer, study finds

February 7, 2018, Cedars-Sinai Medical Center
Diet may influence the spread of a deadly type of breast cancer, study finds
Three-dimensional cell culture of breast cancer cells. Credit: National Institutes of Health (Dao Tiensinh)

A single protein building block commonly found in food may hold a key to preventing the spread of an often-deadly type of breast cancer, according to a new multicenter study published today in the medical journal Nature.

Investigators found that by limiting an amino acid called asparagine in laboratory mice with triple-negative breast cancer, they could dramatically reduce the ability of the cancer to travel to distant sites in the body. Among other techniques, the team used dietary restrictions to limit asparagine.

Foods rich in asparagine include dairy, whey, beef, poultry, eggs, fish, seafood, asparagus, potatoes, legumes, nuts, seeds, soy and whole grains. Foods low in asparagine include most fruits and vegetables.

“Our study adds to a growing body of evidence that suggests diet can influence the course of the disease,” said Simon Knott, PhD, associate director of the Center for Bioinformatics and Functional Genomics at Cedars-Sinai and one of two first authors of the study. The research was conducted at more than a dozen institutions.

If further research confirms the findings in human cells, limiting the amount of asparagine cancer patients ingest could be a potential strategy to augment existing therapies and to prevent the spread of breast cancer, Knott added.

The researchers studied triple-negative breast cancer cells, which grow and spread faster than most other types of cancer cells. It is called triple negative because it lacks receptors for the hormones estrogen and progesterone and makes little of a protein called HER2. As a result, it resists common treatments—which target these factors and has a higher-than-average mortality rate.

Research from past studies found that most tumor cells remain in the primary breast site, but a subset of cells leaves the breast and enters the bloodstream. Those cells colonize in the lungs, brain and liver, where they proliferate. The study team wanted to understand the particular traits of the tumor cells circulating in the blood and in the sites where the cancer has spread.

The researchers discovered that the appearance of asparagine synthetase—the enzyme cells used to make asparagine—in a primary tumor was strongly associated with later cancer spread.

The researchers also found that metastasis was greatly limited by reducing asparagine synthetase, treatment with the chemotherapy drug L-asparaginase, or dietary restriction. When the lab mice were given food rich in asparagine, the cancer cells spread more rapidly.

“The study results are extremely suggestive that changes in diet might impact both how an individual responds to primary therapy and their chances of lethal disease spreading later in life,” said the study’s senior author, Gregory J. Hannon, PhD, professor of Cancer Molecular Biology and director, Cancer Research UK Cambridge Institute, University of Cambridge in England.

Investigators now are considering conducting an early-phase clinical trial in which healthy participants would consume a low-asparagine diet. If the diet results in decreased levels of asparagine, the next scientific step would involve a clinical trial with cancer patients. That trial likely would employ dietary restrictions as well as chemotherapy and immunotherapy, Knott said.

Studying the effects of asparagine also could alter treatments for other types of cancer, investigators say.

“This study may have implications not only for breast cancer, but for many metastatic cancers,” said Ravi Thadhani, MD, MPH, vice dean, Research and Graduate Research Education, at Cedars-Sinai.

 Explore further: Researchers identify specific protein that helps breast cancer to spread

More information: Simon R. V. Knott et al, Asparagine bioavailability governs metastasis in a model of breast cancer, Nature (2018). DOI: 10.1038/nature25465

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Standard of care for localization of impalpable breast lesions, aka Magseed, @ UCSF as First Adopter

Reporter: Aviva Lev-Ari, PhD, RN

PRESS RELEASE

23rd January 2017

  

UCSF first to adopt Magseed as standard of care for localization of impalpable breast lesions

Magseed technology guides surgeons during a breast lumpectomy to simplify treatment and improve patient experience

 

Cambridge, UK & San Francisco, CA, 23rd January 2017: Endomag, the cancer healthcare company, announced today that the University of California, San Francisco (UCSF) has become the first US site to adopt Magseed™ as its standard of care for localization of impalpable breast lesions. Magseed™ is a simpler, more effective alternative to traditional wire localization methods.

 

Breast cancer is the most common form of cancer in women, with 1.7 million new cases of breast cancer globally every year, and is expected to double by 2030. Due to a rise in national screening programmes and an increase in public awareness, breast cancer is being caught at an earlier stage meaning that the tumors are smaller, less defined and harder to feel, with as many as 50% of all breast tumors impalpable at the time of diagnosis. In these cases, a technique called wire localization is typically used by surgeons to locate the tumor.

 

Although widely used, wire localization commonly causes complications. On average 1 in every 4 breast wire localizations result in cancerous tissue being left behind and requiring additional surgery because the wire has become dislodged between when it was implanted and when it was removed during surgery. Additionally, there is a risk of infection due to the wire protruding from the skin, so the placement of the wire must be done on the same day as surgery. These issues result in unnecessary anxiety for patients, delays to the surgical lists and fewer patients being treated as a consequence.

 

Dr. Eric Mayes, CEO of Endomag noted “The wire localization technique has remained largely the same since it was introduced over 30 years ago and it causes a lot of anxiety for patients. We wanted to create a technique that could simplify the localization process and improve the patient experience.”

 

Magseed™ is smaller than a grain of rice and can be placed into the tumor for up to 30 days, allowing the patient to return home ahead of surgery. Once implanted, the seed is not easily dislodged and patients are not restricted in movement or activity. During surgery the seed is detected with the Sentimag® probe to guide accurate removal of the tumor and maximising the amount of healthy tissue left behind. Unlike radioactive alternatives that involve strict regulatory oversight and complex logistics, the Magseed™ technique can be widely adopted by any hospital, regardless of size.

 

Dr. Laura Esserman (Breast Surgeon, UCSF) “We are excited to have a set of safe, easy to use tools that will improve the efficiency of identifying breast lesions and dramatically improve the experience of patients and clinicians, as well as the workflow in the operating room.”

 

 

Dr. Michael Alvarado (Breast Surgeon, UCSF) “We have been looking for a better alternative to wire localization for some time, as the wire procedure adds additional stress for the patients on the day of surgery and often causes delays to our operating schedule. Very early in our evaluation of the magnetic seed technique we found that we could avoid a same-day placement, and the surgeries could be completed in less time, without compromising accuracy. This offers a tangible benefit to both our clinical team and, most importantly, our patients.”

 

ENDS

 

Photo: X-ray showing a complete surgical specimen with negative margins and Magseed™ in the centre, next to the cancer.

For a high res image please contact lorna.cuddon@zymecommunications.com

 

For further information please contact:

Zyme Communications

Lorna Cuddon

Tel: +44 (0)7811 996 942

Email: lorna.cuddon@zymecommunications.com

 

About Endomag http://www.endomag.com 

Endomag is a pioneer in the use of magnetism for minimally-invasive surgical guidance.  By addressing unmet needs in availability, affordability and workflow efficiency for surgical oncology, we support our mission to improve the global standard of cancer care for everyone, everywhere.

 

Founded as a spin-out from the University of Houston and the University College London (UCL) in 2007, we continue to develop our unique clinical platform that uses magnetic fields to power diagnostic and therapeutic devices.  The company has sales in over 30 countries worldwide and is headquartered in Cambridge, United Kingdom.

 

UC Disclaimer

The information stated above was prepared by Endomag, and reflects solely the opinion of the corporation. Nothing in this statement shall be construed to imply any support or endorsement of Endomag, or any of its products, by The Regents of the University of California, its officers, agents and employees.

SOURCE

From: Lorna Cuddon <lorna.cuddon@zymecommunications.com>

Reply-To: <lorna.cuddon@zymecommunications.com>

Date: Monday, January 23, 2017 at 9:16 AM

To: Aviva Lev-Ari <AvivaLev-Ari@alum.berkeley.edu>

Subject: UCSF first to adopt Magseed as standard of care for localization of impalpable breast lesions

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