RESUMEN
PURPOSE: The main aim of the study was to evaluate the potential roles of KRAS/NRAS proto-oncogenes, IL-4 VNTR variants and HPV prevalence in colorectal cancer metastasis. As the second aim, the interactions of the analyzed genes and viral sequences with both clinicopathological variables and each other were targeted. METHODS: DNA was extracted using AmoyDx FFPE DNA Extraction kit from paraffin-embedded colorectal tumor tissue samples (n = 60). NRAS/KRAS mutational profiles were determined with real-time polymerase chain reaction using AmoyDx KRAS/NRAS Mutation Detection Kit. Genotyping of IL-4 VNTR was made with PCR. HPV detection was analyzed by PCR with both GP5+/GP6+ consensus primers and type-specific primers for HPV-16 and HPV-18. SPSS v22 (IBM) statistics software was used for all statistical analyses. RESULTS: From the demographical/clinicopathological parameters, age and biopsy specimens revealed an association with metastasis. KRAS mutation rate was as high as 65 % in the patients and the most prevalent mutation type was G12D. Metastasis risk was 3.19-fold increased in KRAS-mutated patients compared to KRAS-negative ones. IL-4 VNTR genotypes/alleles were not associated with metastasis in our analysis. The frequency of HPVs in our colorectal cancer cohort was 36.7 %, but HPV positivity was not found to be associated with metastasis. A significant association was found between HPV and NRAS mutations; NRAS wild-type status acted as a protective factor by 7.5-fold for HPV negativity. CONCLUSION: Our study comprehensively and concomitantly evaluated several potential molecular risk factors. Future studies designed in such combined approaches will substantially contribute to better manage colorectal cancer tumorigenesis from molecular biological perspective (Tab. 6, Fig. 2, Ref. 40).
Asunto(s)
Neoplasias Colorrectales , Infecciones por Papillomavirus , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , ADN , GTP Fosfohidrolasas/genética , Humanos , Interleucina-4/genética , Proteínas de la Membrana/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Transcription factor proto-oncogene TWIST1 and tumor metastasis suppressor gene LASS2 have been reported to be involved in various carcinomas but their expression profiles and prognostic significances in bladder cancer are largely unknown. We aimed to determine these genes' expression levels both at mRNA and protein level in bladder cancer. mRNA expression levels of TWIST1 and LASS2 genes were examined using real-time quantitative PCR (qPCR) in human bladder tumors and paired normal adjacent tissues obtained from 44 patients. Protein expression profiles of both genes were detected by immunohistochemical staining in formalin-fixed and paraffin-embedded tissues from the same patients. The expression profiles of TWIST1 mRNA in bladder tumors were significantly lower than the normal adjacent tissues and linked to both the stage and the grade. The expression profiles of LASS2 mRNA in bladder tumors were also significantly lower than the normal adjacent tissues reflecting the potential tumor suppressor profile of the gene, independently from stage or grade. By immunohistochemistry, TWIST1 and LASS2 positive expression rates were found as 14.3% (6/42) and 38.1% (16/42), respectively. As potential molecular markers for bladder carcinoma, both TWIST1 and LASS2 transcripts seem to play role during the tumorigenesis and development of bladder cancer. Lack of a functional link and/or weak inverse link between TWIST1 and LASS2 transcripts and immunohistochemical findings may reflect the potential associations of transcription regulation mechanisms and merit further investigations. To the best of our knowledge, this is the first report investigating the combined expression profile of TWIST1 and LASS2 in bladder cancer both at mRNA and protein level.