PRL-3 is essentially overexpressed in primary colorectal tumours and associates with tumour aggressiveness

Phosphatase PRL-3 has been involved in different types of cancer, especially in metastases from colorectal carcinoma (CRC). In this study, we explored both isoforms of PRL-3 as a biomarker to predict the recurrence of stage IIIB-C CRC. Overexpression of PRL-3 was investigated in primary human colorectal tumours (n=20) and hepatic metastases (n=36) xenografted in nude mice, samples characterised by absence of human non-tumoral cells, showing a high degree of expression in metastases (P=0.001). In 27 cases of matched normal colonic mucosa/primary tumour/hepatic metastases, PRL-3 overexpression occurs in primary tumours vs normal mucosa (P=0.001) and in hepatic metastases vs primary tumours (P=0.045). Besides, our results in a series of 80 stage IIIB-C CRC primary tumours showed that high levels of PRL-3 were an independent predictor of metastasis (P<0.0001; OR: 9.791) in multivariate analysis of a binary logistic regression and that PRL-3 expression tightly correlates with parameters of bad outcome. Moreover, PRL-3 expression associated with poor outcome in univariate (P<0.0001) and multivariate Cox models (hazard ratio: 3.322, 95%, confidence interval: 1.405-7.852, P=0.006). In conclusion, PRL-3 is a good marker of aggressiveness of locally advanced CRS and a promising predictor of distant metastases. Nevertheless, for prognosis purposes, it is imperative to validate the cutoff value of PRL-3 expression in a larger and consecutive series and adjuvant setting

A hotspot for posttranslational modifications on the androgen receptor dimer interface drives pathology and anti-androgen resistance

Mutations of the androgen receptor (AR) associated with prostate cancer and androgen insensitivity syndrome may profoundly influence its structure, protein interaction network, and binding to chromatin, resulting in altered transcription signatures and drug responses. Current structural information fails to explain the effect of pathological mutations on AR structure-function relationship. Here, we have thoroughly studied the effects of selected mutations that span the complete dimer interface of AR ligand-binding domain (AR-LBD) using x-ray crystallography in combination with in vitro, in silico, and cell-based assays. We show that these variants alter AR-dependent transcription and responses to anti-androgens by inducing a previously undescribed allosteric switch in the AR-LBD that increases exposure of a major methylation target, Arg761. We also corroborate the relevance of residues Arg761 and Tyr764 for AR dimerization and function. Together, our results reveal allosteric coupling of AR dimerization and posttranslational modifications as a disease mechanism with implications for precision medicine

Estudi genètic integral de la regió 4p15 i identificació de PI4K2B i STIM2 com a gens alterats en càncer colorectal

[cat] DE LA TESI: El diagrama complet de les pertorbacions genètiques i epigenètiques que afecten el càncer colorectal (CCR) està lluny de ser totalment conegut. L'LOH és una de les alteracions més recurrents en CCR així com en d'altres neoplàsies. Acostuma a ser un bon indicador de la presència de gens rellevants per a la carcinogènesi. L'estudi de les alteracions somàtiques en gens situats en aquestes regions recurrents de desequilibri al·lèlic ha estat fonamental en el passat per la identificació d'alguns dels gens supressors tumorals més coneguts, com és el cas de p53, Smad4, p16, APC o Rb. Els desequilibris al·lèlics a 4p s'han associat amb una major agressivitat i un pitjor pronòstic en pacients de CCR, malgrat que els gens diana d'aquests alteracions resten encara per ser identificats. En aquesta tesi s'ha dut a terme un treball d'anàlisi genètica integral per a una regió crítica situada a 4p15 am la intenció de localitzar-hi els gens que més probablement estiguin contribuint a la progressió tumoral. Hem realitzat un exhaustiu treball d'al·lotipat mitjançant la utilització de marcadors microsatèl·lit, sobre un model de tumors xenoempeltats en ratolins atímics. Hem identificat una regió crítica en al que els gens candidats han estat analitzats d'acord a les seves possibles alteracions somàtiques genètiques i/o epigenètiques. També hem analitzat els patrons d'expressió dels gens candidats per tal d'identificar possibles alteracions transcripcionals. Mitjançant prediccions de regulació transcripcional bioinformàtiques hem trobat que PI4K2B i STIM2 són dos gens regulats per TCF4/B-catenina. Això ha estat confirmat mitjançant immunoprecipitació de cromatines. Hem avaluat el valor pronòstic de les alteracions en aquests dos gens i el seu valor com predictors de la resposta al tractament basat en el 5-FU de pacients de CCR. A més, hem realitzat experiments de depleció mitjançada per siRNA sobre línies cel·lulars de CCR, alhora que hem transfectat de forma estable aquests dos gens. Finalment hem realitzat assajos de formació de tumors en ratolins immunodeprimits per comprovar si la sobreexpressió dels nostres gens candidats té o no un efecte en la formació dels tumors generats a partir de línies cel·lulars. Els patrons de LOH identificats a 4p descarten que, com s'havia proposat, es doni en l'estadi metastàtic una acumulació d'aquestes alteracions. L'LOH detectat no correlaciona amb la dosi gènica, és a dir que les pèrdues d'heterozigositat no comporten una pèrdua de material genètic i probablement són la conseqüència de processos de recombinació mitòtica i/o pèrdua i duplicació associats a un escenari d'inestabilitat cromosòmica. Els gens d'aquesta regió crítica no són portadors de mutacions, microdelecions ni delecions en homozigosi, ni tampoc presenten alteracions en els patrons de metilació de les seves regions promotores. Per contra, vam trobar que PI4K2B i STIM2 estaven significativament sobreexpressats en pacients afectes de CCR i metàstasi hepàtiques (MH) independentment de la presència o no d'LOH, i que, a més, la seva transcripció estava sot control del complex TCF4/B-catenina. Els nivells elevats de PI4K2B, tant de proteïna com d'mRNA estan assocats a un millor pronòstic i una millor resposta al tractament quimioteràpic dels pacients de CCR. Finalment, els estudis de depleció amb siRNA han demostrat que el silenciament d'aquests dos gens comporta un increment significatiu de la proliferació cel·lular i que la sobreexpressió en línies cel·lulars de STIM2 resulta en una disminució del volum tumoral i per tant té un efecte de supressió de la proliferació. Conclusions: Hem identificat PI4K2B i STIM2 com a gens diana de les alteracions recurrents a 4p15 i hem demostrat que són dianes transcripcional de la via de B-catenina. La sobreexpressió d'aquests dos gens té un efecte supressor de la proliferació cel·lular, que alhora, té un impacte en el pronòstic i el tractament dels pacients de càncer colorectal

PRL-3 overexpression in epithelial cells is induced by surrounding stromal fibroblasts

We isolate and culture carcinoma-associated fibroblasts (CAFs) from primary tumour (CAFpt), CAFs from corresponding synchronous liver metastasis (CAFlm) as well as normal colonic fibroblasts (NCF) from the same patient. From these cultures, conditioned media (CM) was obtained. Culture of a wide panel of colorectal and pancreatic cell lines in CM from CAFlm resulted in overexpression of mRNA PRL-3 and higher overexpression in CAFs than in non-activated fibroblasts. Moreover PRL-3 mRNA expression correlates with expression of alpha-SMA and deposition of collagen fibrils in the stroma. We demonstrate that products secreted by CAFs trigger PRL-3 overexpression in cancer cells. Identification of these factors may contribute to new stroma-targeted therapies for desmoplastic tumour

PRL-3 overexpression in epithelial cells is induced by surrounding stromal fibroblasts

We isolate and culture carcinoma-associated fibroblasts (CAFs) from primary tumour (CAFpt), CAFs from corresponding synchronous liver metastasis (CAFlm) as well as normal colonic fibroblasts (NCF) from the same patient. From these cultures, conditioned media (CM) was obtained. Culture of a wide panel of colorectal and pancreatic cell lines in CM from CAFlm resulted in overexpression of mRNA PRL-3 and higher overexpression in CAFs than in non-activated fibroblasts. Moreover PRL-3 mRNA expression correlates with expression of alpha-SMA and deposition of collagen fibrils in the stroma. We demonstrate that products secreted by CAFs trigger PRL-3 overexpression in cancer cells. Identification of these factors may contribute to new stroma-targeted therapies for desmoplastic tumour

PRL-3 is essentially overexpressed in primary colorectal tumours and associates with tumour aggressiveness

Phosphatase PRL-3 has been involved in different types of cancer, especially in metastases from colorectal carcinoma (CRC). In this study, we explored both isoforms of PRL-3 as a biomarker to predict the recurrence of stage IIIB-C CRC. Overexpression of PRL-3 was investigated in primary human colorectal tumours (n=20) and hepatic metastases (n=36) xenografted in nude mice, samples characterised by absence of human non-tumoral cells, showing a high degree of expression in metastases (P=0.001). In 27 cases of matched normal colonic mucosa/primary tumour/hepatic metastases, PRL-3 overexpression occurs in primary tumours vs normal mucosa (P=0.001) and in hepatic metastases vs primary tumours (P=0.045). Besides, our results in a series of 80 stage IIIB-C CRC primary tumours showed that high levels of PRL-3 were an independent predictor of metastasis (P<0.0001; OR: 9.791) in multivariate analysis of a binary logistic regression and that PRL-3 expression tightly correlates with parameters of bad outcome. Moreover, PRL-3 expression associated with poor outcome in univariate (P<0.0001) and multivariate Cox models (hazard ratio: 3.322, 95%, confidence interval: 1.405-7.852, P=0.006). In conclusion, PRL-3 is a good marker of aggressiveness of locally advanced CRS and a promising predictor of distant metastases. Nevertheless, for prognosis purposes, it is imperative to validate the cutoff value of PRL-3 expression in a larger and consecutive series and adjuvant setting

PRL-3 is essentially overexpressed in primary colorectal tumours and associates with tumour aggressiveness

Phosphatase PRL-3 has been involved in different types of cancer, especially in metastases from colorectal carcinoma (CRC). In this study, we explored both isoforms of PRL-3 as a biomarker to predict the recurrence of stage IIIB-C CRC. Overexpression of PRL-3 was investigated in primary human colorectal tumours (n=20) and hepatic metastases (n=36) xenografted in nude mice, samples characterised by absence of human non-tumoral cells, showing a high degree of expression in metastases (P=0.001). In 27 cases of matched normal colonic mucosa/primary tumour/hepatic metastases, PRL-3 overexpression occurs in primary tumours vs normal mucosa (P=0.001) and in hepatic metastases vs primary tumours (P=0.045). Besides, our results in a series of 80 stage IIIB-C CRC primary tumours showed that high levels of PRL-3 were an independent predictor of metastasis (P<0.0001; OR: 9.791) in multivariate analysis of a binary logistic regression and that PRL-3 expression tightly correlates with parameters of bad outcome. Moreover, PRL-3 expression associated with poor outcome in univariate (P<0.0001) and multivariate Cox models (hazard ratio: 3.322, 95%, confidence interval: 1.405-7.852, P=0.006). In conclusion, PRL-3 is a good marker of aggressiveness of locally advanced CRS and a promising predictor of distant metastases. Nevertheless, for prognosis purposes, it is imperative to validate the cutoff value of PRL-3 expression in a larger and consecutive series and adjuvant setting

Taxane-induced attenuation of the CXCR2/BCL-2 axis aensitizes prostate cancer to platinum-based treatment

Background: Taxanes are the most active chemotherapy agents in metastatic castration-resistant prostate cancer (mCRPC) patients; yet, resistance occurs almost invariably, representing an important clinical challenge. Taxane-platinum combinations have shown clinical benefit in a subset of patients, but the mechanistic basis and biomarkers remain elusive. Objective: To identify mechanisms and response indicators for the antitumor efficacy of taxane-platinum combinations in mCRPC. Design, setting, and participants: Transcriptomic data from a publicly available mCRPC dataset of taxane-exposed and taxane-naïve patients were analyzed to identify response indicators and emerging vulnerabilities. Functional and preclinical validation was performed in taxane-resistant mCRPC cell lines and genetically engineered mouse models (GEMMs). Intervention: Metastatic CRPC cells were treated with docetaxel, cisplatin, carboplatin, the CXCR2 antagonist SB265610, and the BCL-2 inhibitor venetoclax. Gain and loss of function in culture of CXCR2 and BCL-2 were achieved by overexpression or siRNA silencing. Preclinical assays in GEMM mice tested the antitumor efficacy of taxane-platinum combinations. Outcome measurements and statistical analysis: Proliferation, apoptosis, and colony assays measured drug activity in vitro. Preclinical endpoints in mice included growth, survival, and histopathology. Changes in CXCR2, BCL-2, and chemokines were analyzed by reverse transcriptase quantitative polymerase chain reaction and Western blot. Human expression data were analyzed using Gene Set Enrichment Analysis, hierarchical clustering, and correlation studies. GraphPad Prism software and R-studio were used for statistical and data analyses. Results and limitations: Transcriptomic data from taxane-exposed human mCRPC tumors correlate with a marked negative enrichment of apoptosis and inflammatory response pathways accompanied by a marked downregulation of CXCR2 and BCL-2. Mechanistically, we show that docetaxel inhibits CXCR2 and that BCL-2 downregulation occurs as a downstream effect. Further, we demonstrated in experimental models that the sensitivity to cisplatin is dependent on CXCR2 and BCL-2, and that targeting them sensitizes prostate cancer (PC) cells to cisplatin. In vivo taxane-platinum combinations are highly synergistic, and previous exposure to taxanes sensitizes mCRPC tumors to second-line cisplatin treatment. Conclusions: The hitherto unappreciated attenuation of the CXCR2/BCL-2 axis in taxane-treated mCRPC patients is an acquired vulnerability with potential predictive activity for platinum-based treatments. Patient summary: A subset of patients with aggressive and therapy-resistant prostate cancer benefits from taxane-platinum combination chemotherapy; however, we lack the mechanistic understanding of how that synergistic effect occurs. Here, using patient data and preclinical models, we found that taxanes reduce cancer cell escape mechanisms to chemotherapy-induced cell death, hence making these cells more vulnerable to additional platinum treatment.This work was supported by funding from the “Badalona Foundation Against Cancer” grant (Albert Font) and from Instituto de Salut Carlos III (PI16/01070 and CP15/00090; Alvaro Aytes), the European Association of Urology Research Foundation (EAURF/407003/XH; Alvaro Aytes),Fundacion BBVA (Alvaro Aytes), Department of Defense Award (W81XWH-18-1-0193; Alvaro Aytes), the CERCA Program/Generalitat de Catalunya (Alvaro Aytes), and FEDER funds/European Regional Development Fund (ERDF)—a way to Build Europe (Alvaro Aytes

Correction for Melo et al., Small molecule enoxacin is a cancer-specific growth inhibitor that acts by enhancing TAR RNA-binding protein 2-mediated microRNA processing

Medical sciences: correction for "Small molecule enoxacin is a cancer-specific growth inhibitor that acts by enhancing TAR RNA-binding protein 2-mediated microRNA processing," by SoniaMelo, Alberto Villanueva, Catia Moutinho, Veronica Davalos, Riccardo Spizzo, Cristina Ivan, Simona Rossi, Fernando Setien, Oriol Casanovas, Laia Simo-Riudalbas, Javier Carmona, Jordi Carrere, August Vidal, Alvaro Aytes, Sara Puertas, Santiago Ropero, Raghu Kalluri, Carlo M. Croce, George A. Calin, and Manel Esteller, which appeared in issue 11, March 15, 2011, of Proc Natl Acad Sci USA (108:4394-4399; first published February 28, 2011; 10.1073/pnas.1014720108)

Interplay between BRCA1 and RHAMM Regulates Epithelial Apicobasal Polarization and May Influence Risk of Breast Cancer.

Differentiated mammary epithelium shows apicobasal polarity, and loss of tissue organization is an early hallmark of breast carcinogenesis. In BRCA1 mutation carriers, accumulation of stem and progenitor cells in normal breast tissue and increased risk of developing tumors of basal-like type suggest that BRCA1 regulates stem/progenitor cell proliferation and differentiation. However, the function of BRCA1 in this process and its link to carcinogenesis remain unknown. Here we depict a molecular mechanism involving BRCA1 and RHAMM that regulates apicobasal polarity and, when perturbed, may increase risk of breast cancer. Starting from complementary genetic analyses across families and populations, we identified common genetic variation at the low-penetrance susceptibility HMMR locus (encoding for RHAMM) that modifies breast cancer risk among BRCA1, but probably not BRCA2, mutation carriers: n = 7,584, weighted hazard ratio (wHR) = 1.09 (95% CI 1.02-1.16), ptrend = 0.017; and n = 3,965, wHR = 1.04 (95% CI 0.94-1.16), ptrend = 0.43; respectively. Subsequently, studies of MCF10A apicobasal polarization revealed a central role for BRCA1 and RHAMM, together with AURKA and TPX2, in essential reorganization of microtubules. Mechanistically, reorganization is facilitated by BRCA1 and impaired by AURKA, which is regulated by negative feedback involving RHAMM and TPX2. Taken together, our data provide fundamental insight into apicobasal polarization through BRCA1 function, which may explain the expanded cell subsets and characteristic tumor type accompanying BRCA1 mutation, while also linking this process to sporadic breast cancer through perturbation of HMMR/RHAMM