ABCC5 supports osteoclast formation and promotes breast cancer metastasis to bone

INTRODUCTION: Bone is the most common site of breast cancer metastasis, and complications associated with bone metastases can lead to a significantly decreased patient quality of life. Thus, it is essential to gain a better understanding of the molecular mechanisms that underlie the emergence and growth of breast cancer skeletal metastases. METHODS: To search for novel molecular mediators that influence breast cancer bone metastasis, we generated gene-expression profiles from laser-capture microdissected trephine biopsies of both breast cancer bone metastases and independent primary breast tumors that metastasized to bone. Bioinformatics analysis identified genes that are differentially expressed in breast cancer bone metastases compared with primary, bone-metastatic breast tumors. RESULTS: ABCC5, an ATP-dependent transporter, was found to be overexpressed in breast cancer osseous metastases relative to primary breast tumors. In addition, ABCC5 was significantly upregulated in human and mouse breast cancer cell lines with high bone-metastatic potential. Stable knockdown of ABCC5 substantially reduced bone metastatic burden and osteolytic bone destruction in mice. The decrease in osteolysis was further associated with diminished osteoclast numbers in vivo. Finally, conditioned media from breast cancer cells with reduced ABCC5 expression failed to induce in vitro osteoclastogenesis to the same extent as conditioned media from breast cancer cells expressing ABCC5. CONCLUSIONS: Our data suggest that ABCC5 functions as a mediator of breast cancer skeletal metastasis. ABCC5 expression in breast cancer cells is important for efficient osteoclast-mediated bone resorption. Hence, ABCC5 may be a potential therapeutic target for breast cancer bone metastasis

Projected economic losses from milk performance detriments under heat stress in Qubec dairy herds.

The objective of this study was to estimate economic losses associated with milk performance detriments under different climate scenarios. A dataset containing milk records of Holstein and daily temperature-humidity indexes compiled over 6 years in two contrasting climatic dairy regions of Quebec Province [Eastern and Southwestern Quebec] was used to develop equations for modeling milk performance. Milk performance, including milk, fat, protein, and lactose yields of dairy herds (kg j-1), were then projected considering six plausible climate scenarios during a climatic reference period [REF: 1971 to 2000] and two future periods [FUT1: 2020 to 2049; FUT2: 2050 to 2079]. Economic losses were assessed by comparing future to reference milk prices based on components. Results indicated that fat and protein yields could decline in the future, thus resulting in economic losses ranging from 5.34 to 7.07 can$hL-1 in Eastern Quebec, and from 5.03 to 6.99 can$ hL-1 in Southwestern Quebec, depending on the amplitude of future temperature and humidity changes and on whether it is milk quota or cow number which is adjusted to avoid under-quota production. The projected increase in occurrence and duration of heat stress episodes under climate change could result in substantial financial harm for producers, thereby reinforcing the necessity of implementing heat-abatement strategies on dairy farms.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Elevated Expression of Glycerol-3-Phosphate Phosphatase as a Biomarker of Poor Prognosis and Aggressive Prostate Cancer

The limitations of the biomarker prostate-specific antigen (PSA) necessitate the pursuit of biomarkers capable of better identifying high-risk prostate cancer (PC) patients in order to improve their therapeutic management and outcomes. Aggressive prostate tumors characteristically exhibit high rates of glycolysis and lipogenesis. Glycerol 3-phosphate phosphatase (G3PP), also known as phosphoglycolate phosphatase (PGP), is a recently identified mammalian enzyme, shown to play a role in the regulation of glucose metabolism, lipogenesis, lipolysis, and cellular nutrient-excess detoxification. We hypothesized that G3PP may relieve metabolic stress in cancer cells and assessed the association of its expression with PC patient prognosis. Using immunohistochemical staining, we assessed the epithelial expression of G3PP in two different radical prostatectomy (RP) cohorts with a total of 1797 patients, for whom information on biochemical recurrence (BCR), metastasis, and mortality was available. The association between biomarker expression, biochemical recurrence (BCR), bone metastasis, and prostate cancer-specific survival was established using log-rank and multivariable Cox regression analyses. High expression of G3PP in PC epithelial cells is associated with an increased risk of BCR, bone metastasis, and PC-specific mortality. Multivariate analysis revealed high G3PP expression in tumors as an independent predictor of BCR and bone metastasis development. High G3PP expression in tumors from patients eligible for prostatectomies is a new and independent prognostic biomarker of poor prognosis and aggressive PC for recurrence, bone metastasis, and mortality

V-ATPase-associated prorenin receptor is upregulated in prostate cancer after PTEN loss

Phosphatase and tensin homolog (PTEN) tumor suppressor protein loss is common in prostate cancer (PCa). PTEN loss increases PI3K/Akt signaling, which promotes cell growth and survival. To find secreted biomarkers of PTEN loss, a proteomic screen was used to compare secretomes of cells with and without PTEN expression. We showed that PTEN downregulates Prorenin Receptor (PRR) expression and secretion of soluble Prorenin Receptor (sPRR) in PCa cells and in mouse. PRR is an accessory protein required for assembly of the vacuolar ATPase (V-ATPase) complex. V-ATPase is required for lysosomal acidification, amino acid sensing, efficient mechanistic target of Rapamycin complex 1 (mTORC1) activation, and β-Catenin signaling. On PCa tissue microarrays, PRR expression displayed a positive correlation with Akt phosphorylation. Moreover, PRR expression was required for proliferation of PCa cells by maintaining V-ATPase function. Further, we provided evidence for a potential clinical role for PRR expression and sPRR concentration in differentiating low from high Gleason grade PCa. Overall, the current study unveils a mechanism by which PTEN can inhibit tumor growth. Lower levels of PRR result in attenuated V-ATPase activity and reduced PCa cell proliferation

Describing perspectives of health care professionals on active surveillance for the management of prostate cancer

Background: Over the last decade, active surveillance has proven to be a safe approach for patients with low-risk prostate cancer. Although active surveillance presents several advantages for both patients and the health care system, all eligible patients do not adopt this approach. Our goal was to evaluate the factors that influence physicians to recommend active surveillance and the barriers that impact adherence to this approach. Methods: Focus groups (n = 5) were held with physicians who provided care for men with low-risk prostate cancer and had engaged in conversations with men and their families about active surveillance. The experience of health care professionals (HCPs) was captured to understand their decisions in proposing active surveillance and to reveal the barriers and facilitators that affect the adherence to this approach. A content analysis was performed on the verbatim transcripts from the sessions. Results: Although physicians agreed that active surveillance is a suitable approach for low-risk prostate cancer patients, they were concerned about the rapidly evolving and non-standardized guidelines for patient follow-up. They pointed out the need for additional tools to appropriately identify proper patients for whom active surveillance is the best option. Urologists and radiation-oncologists were keen to collaborate with each other, but the role of general practitioner remained controversial once patients were referred to a specialist. Conclusions: Integration of more reliable tools and/or markers in addition to more specific guidelines for patient follow-up would increase the confidence of both patients and physicians in the choice of active surveillance.Other UBCNon UBCReviewedFacult

Le Cri du peuple : journal politique quotidien

28 janvier 18881888/01/28 (A5,N1552)-1888/01/28

Le Cri du peuple : journal politique quotidien

27 avril 18911891/04/27 (A11,N13)-1891/04/27

Canadian Men’s perspectives about active surveillance in prostate cancer: need for guidance and resources

Background: In prostate cancer, men diagnosed with low risk disease may be monitored through an active surveillance. This research explored the perspectives of men with prostate cancer regarding their decision-making process for active surveillance to identify factors that influence their decision and assist health professionals in having conversations about this option. Methods: Focus group interviews (n = 7) were held in several Canadian cities with men (N = 52) diagnosed with prostate cancer and eligible for active surveillance. The men’s viewpoints were captured regarding their understanding of active surveillance, the factors that influenced their decision, and their experience with the approach. A content and theme analysis was performed on the verbatim transcripts from the sessions. Results: Patients described their concerns of living with their disease without intervention, but were reassured by the close monitoring under AS while avoiding harmful side effects associated with treatments. Conversations with their doctor and how AS was described were cited as key influences in their decision, in addition to availability of information on treatment options, distrust in the health system, personality, experiences and opinions of others, and personal perspectives on quality of life. Conclusions: Men require a thorough explanation on AS as a safe and valid option, as well as guidance towards supportive resources in their decision-making.Other UBCNon UBCReviewedFacult