Detección e integración del virus del papiloma humano de alto riesgo en lesiones pre-neoplásicas en mujeres del sur de Chile: un estudio transversal / High-risk human papillomavirus detection and integration in preneoplastic lesions among women in Southern Chile: a cross-sectional study

INTRODUCCIÓN: El virus del papiloma humano de alto riesgo (VPH-AR) es responsable del cáncer de cuello uterino y sus lesiones preneoplásicas. Los genotipos VPH16 y VPH18 son los más frecuentes en este cáncer. La integración del VPH-AR en el genoma de la célula hospedera es crucial en la carcinogénesis cervical, pero la etapa en que ocurre en la población chilena es incierta. OBJETIVO: Evaluar la integración de VPH16 y VPH18 en lesiones pre-neoplásicas de cuello uterino. MÉTODOS: Se analizaron 108 muestras de raspados cervicales. El VPH se genotipificó mediante reacción de polimerasa en cadena (RPC) e hibridación no radiactiva. La integración de VPH16 y VPH18 se determinó por presencia del gen E2 mediante RPC. RESULTADOS: VPH16 y VPH18 se detectaron en 36,1% y 12,0% de las muestras, respectivamente. El VPH16 se integró en 23,1% de los casos de VPH16, mientras que VPH18 se integró en 100% de las muestras positivas para este genotipo. CONCLUSIONES: La integración VPH-AR es un evento temprano en la carcinogénesis cervical que ocurre en casi la mitad de las lesiones pre-neoplásicas y es más frecuente en VPH18 que en VPH16. La evaluación de la integración VPH-AR puede ser una herramienta útil para detectar el virus en la población chilena.

BACKGROUND: High-risk Human Papillomaviruses (HR-HPVs) are the etiological agents of cervical cancer and its preneoplastic lesions. HPV16 and 18 are the most frequent HR-HPV genotypes detected in cervical cancer. HR-HPV genome integration into the host cell is an important event in the carcinogenic process. However, it remains uncertain which stage of cervical carcinogenesis HPV16 and 18 integration occurs in the Chilean population. AIM: The goal of this study was to evaluate HPV16 and HPV18 integration in preneoplastic lesions of the cervix. METHODS: DNA was extracted from 108 cervical scrape samples with preneoplastic lesions. HPV was genotyped using PCR and non-radioactive hybridization. The integration status of HPV16 and HPV 18 was determined by evaluating the E2 gene presence through PCR. RESULTS: HPV16 and HPV18 tested positive in 36.1% and 12.0% of samples, respectively. HPV16 was found integrated in 23.1% of HPV 16 cases, while HPV 18 in 100% of samples positive for this viral genotype. CONCLUSIONS: HR-HPV integration is an early event in cervical carcinogenesis, occurring in nearly half of preneoplastic lesions and being more frequent in HPV18 than in HPV16. The evaluation of HR-HPV integration can be utilized as a complementary tool for detecting HPV in the Chilean population.

Functional and transcriptomic characterization of carboplatin-resistant A2780 ovarian cancer cell line

BACKGROUND: Ovarian cancer is a significant cancer-related cause of death in women worldwide. The most used chemotherapeutic regimen is based on carboplatin (CBDCA). However, CBDCA resistance is the main obstacle to a better prognosis. An in vitro drug-resistant cell model would help in the understanding of molecular mechanisms underlying this drug-resistance phenomenon. The aim of this study was to characterize cellular and molecular changes of induced CBDCA-resistant ovarian cancer cell line A2780. METHODS: The cell selection strategy used in this study was a dose-per-pulse method using a concentration of 100 µM for 2 h. Once 20 cycles of exposure to the drug were completed, the cell cultures showed a resistant phenotype. Then, the ovarian cancer cell line A2780 was grown with 100 µM of CBDCA (CBDCA-resistant cells) or without CBDCA (parental cells). After, a drug sensitivity assay, morphological analyses, cell death assays and a RNA-seq analysis were performed in CBDCA-resistant A2780 cells. RESULTS: Microscopy on both parental and CBDCA-resistant A2780 cells showed similar characteristics in morphology and F-actin distribution within cells. In cell-death assays, parental A2780 cells showed a significant increase in phosphatidylserine translocation and caspase-3/7 cleavage compared to CBDCA-resistant A2780 cells (P < 0.05 and P < 0.005, respectively). Cell viability in parental A2780 cells was significantly decreased compared to CBDCA-resistant A2780 cells (P < 0.0005). The RNA-seq analysis showed 156 differentially expressed genes (DEGs) associated mainly to molecular functions. CONCLUSION: CBDCA-resistant A2780 ovarian cancer cells is a reliable model of CBDCA resistance that shows several DEGs involved in molecular functions such as transmembrane activity, protein binding to cell surface receptor and catalytic activity. Also, we found that the Wnt/3-catenin and integrin signaling pathway are the main metabolic pathway dysregulated in CBDCA-resistant A2780 cells.

Reprimo as a modulator of cell migration and invasion in the MDA-MB-231 breast cancer cell line

BACKGROUND: Reprimo (RPRM), a highly glycosylated protein, is a new downstream effector of p53-induced cell cycle arrest at the G2/M checkpoint, and a putative tumor suppressor gene frequently silenced via methylation of its promoter region in several malignances. The aim of this study was to characterize the epigenetic inactivation and its biological function in BC cell lines. METHODS: The correlation between RPRM methylation and loss of mRNA expression was assessed in six breast cancer cell lines by methylation specific PCR (MSP), 5'-Aza-2'-deoxycytidine treatment and RT-PCR assays. MDA-MB-231 cells were chosen to investigate the phenotypic effect of RPRM in cell proliferation, cell cycle, cell death, cell migration and invasion. RESULTS: In the cancer methylome system (CMS) (web-based system for visualizing and analyzing genome-wide methylation data of human cancers), the CpG island region of RPRM (1.1 kb) was hypermethylated in breast cancer compared to normal breast tissue; more interesting still was that ERa(+) tumors showed higher methylation intensity than ERa(-). Downregulation of RPRM mRNA by methylation was confirmed in MDA-MB-231 and BT-20 cell lines. In addition, overexpression of RPRM in MDA-MB-231 cells resulted in decreased rates of cell migration, wound healing and invasion in vitro. However, RPRM overexpression did not alter cell viability, phosphatidylserine (PS) translocation or G2/M cell cycle transition. CONCLUSION: Taken together, these data suggest that RPRM is involved in decreased cell migration and invasion in vitro, acting as a potential tumor suppressor gene in the MDA-MB-231 cell line.