Mechanisms of inactivation of the tumour suppressor gene RHOA in colorectal cancer

Background: Reduced RHOA signalling has been shown to increase the growth/metastatic potential of colorectal tumours. However, the mechanisms of inactivation of RHOA signalling in colon cancer have not been characterised.Methods:A panel of colorectal cancer cell lines and large cohorts of primary tumours were used to investigate the expression and activity of RHOA, as well as the presence of RHOA mutations/deletions and promoter methylation affecting RHOA. Changes in RHOA expression were assessed by western blotting and qPCR after modulation of microRNAs, SMAD4 and c-MYC.Results:We show here that RHOA point mutations and promoter hypermethylation do not significantly contribute to the large variability of RHOA expression observed among colorectal tumours. However, RHOA copy number loss was observed in 16% of colorectal tumours and this was associated with reduced RHOA expression. Moreover, we show that miR-200a/b/429 downregulates RHOA in colorectal cancer cells. In addition, we found that TGF-β/SMAD4 upregulates the RHOA promoter. Conversely, RHOA expression is transcriptionally downregulated by canonical Wnt signalling through the Wnt target gene c-MYC that interferes with the binding of SP1 to the RHOA promoter in colon cancer cells.Conclusions:We demonstrate a complex pattern of inactivation of the tumour suppressor gene RHOA in colon cancer cells through genetic, transcriptional and post-transcriptional mechanisms.</p

Data_Sheet_1_Determinants of HIV late presentation among men who have sex with men in Portugal (2014–2019): who’s being left behind?.docx

IntroductionHIV late presentation (LP) remains excessive in Europe. We aimed to analyze the factors associated with late presentation in the MSM population newly diagnosed with HIV in Portugal between 2014 and 2019.MethodsWe included 391 newly HIV-1 diagnosed Men who have Sex with Men (MSM), from the BESTHOPE project, in 17 countrywide Portuguese hospitals. The data included clinical and socio-behavioral questionnaires and the viral genomic sequence obtained in the drug resistance test before starting antiretrovirals (ARVs). HIV-1 subtypes and epidemiological surveillance mutations were determined using different bioinformatics tools. Logistic regression was used to estimate the association between predictor variables and late presentation (LP).ResultsThe median age was 31 years, 51% had a current income between 501–1,000 euros, 28% were migrants. 21% had never been tested for HIV before diagnosis, with 42.3% of MSM presenting LP. 60% were infected with subtype B strains. In the multivariate regression, increased age at diagnosis, higher income, lower frequency of screening, STI ever diagnosed and higher viral load were associated with LP.ConclusionOur study suggests that specific subgroups of the MSM population, such older MSM, with higher income and lower HIV testing frequency, are not being targeted by community and clinical screening services. Overall, targeted public health measures should be strengthened toward these subgroups, through strengthened primary care testing, expanded access to PrEP, information and promotion of HIV self-testing and more inclusive and accessible health services.</p

Data_Sheet_1_Determinants of HIV late presentation among men who have sex with men in Portugal (2014–2019): who’s being left behind?.docx

IntroductionHIV late presentation (LP) remains excessive in Europe. We aimed to analyze the factors associated with late presentation in the MSM population newly diagnosed with HIV in Portugal between 2014 and 2019.MethodsWe included 391 newly HIV-1 diagnosed Men who have Sex with Men (MSM), from the BESTHOPE project, in 17 countrywide Portuguese hospitals. The data included clinical and socio-behavioral questionnaires and the viral genomic sequence obtained in the drug resistance test before starting antiretrovirals (ARVs). HIV-1 subtypes and epidemiological surveillance mutations were determined using different bioinformatics tools. Logistic regression was used to estimate the association between predictor variables and late presentation (LP).ResultsThe median age was 31 years, 51% had a current income between 501–1,000 euros, 28% were migrants. 21% had never been tested for HIV before diagnosis, with 42.3% of MSM presenting LP. 60% were infected with subtype B strains. In the multivariate regression, increased age at diagnosis, higher income, lower frequency of screening, STI ever diagnosed and higher viral load were associated with LP.ConclusionOur study suggests that specific subgroups of the MSM population, such older MSM, with higher income and lower HIV testing frequency, are not being targeted by community and clinical screening services. Overall, targeted public health measures should be strengthened toward these subgroups, through strengthened primary care testing, expanded access to PrEP, information and promotion of HIV self-testing and more inclusive and accessible health services.</p

Data_Sheet_1_Determinants of HIV late presentation among men who have sex with men in Portugal (2014–2019): who’s being left behind?.docx

IntroductionHIV late presentation (LP) remains excessive in Europe. We aimed to analyze the factors associated with late presentation in the MSM population newly diagnosed with HIV in Portugal between 2014 and 2019.MethodsWe included 391 newly HIV-1 diagnosed Men who have Sex with Men (MSM), from the BESTHOPE project, in 17 countrywide Portuguese hospitals. The data included clinical and socio-behavioral questionnaires and the viral genomic sequence obtained in the drug resistance test before starting antiretrovirals (ARVs). HIV-1 subtypes and epidemiological surveillance mutations were determined using different bioinformatics tools. Logistic regression was used to estimate the association between predictor variables and late presentation (LP).ResultsThe median age was 31 years, 51% had a current income between 501–1,000 euros, 28% were migrants. 21% had never been tested for HIV before diagnosis, with 42.3% of MSM presenting LP. 60% were infected with subtype B strains. In the multivariate regression, increased age at diagnosis, higher income, lower frequency of screening, STI ever diagnosed and higher viral load were associated with LP.ConclusionOur study suggests that specific subgroups of the MSM population, such older MSM, with higher income and lower HIV testing frequency, are not being targeted by community and clinical screening services. Overall, targeted public health measures should be strengthened toward these subgroups, through strengthened primary care testing, expanded access to PrEP, information and promotion of HIV self-testing and more inclusive and accessible health services.</p