Rodolfo Ocadiz-Delgado

The vaginal and fecal microbiota of a murine cervical carcinoma model under synergistic effect of 17β-Estradiol and E7 oncogene expression

Cervical cancer is an important health issue worldwide. Many factors are related to this condition as the persistence of human papillomavirus (HPV) infection (e.g. type 16 and 18), the use of hormonal contraceptives for long periods of time, pH changes and bacterial vaginosis. The association between the microbiota and cervical human cancer is an interesting issue to be explored; given that environmental and hormonal factors may change the vaginal microbiota contributing to this condition. Our hypothesis was that changes in the microbiota diversity is associated with the development of cervical cancer. We evaluated the microbiota diversity in vaginal lavages and fecal samples at different stages of cervical cancer development in a mice model (K14HPV16E7) with type 16 E7 oncogene expression (E7), under continuous or not continuous stimulus of 17β-estradiol (E2) and compared it with a non-transgenic isogenic control (FVB) under same conditions. Our results indicate that continuous E2 administration during 6 months in the model with type 16 E7 expression causing development of cancer, is associated with significant changes in the microbiota diversity of the cervicovaginal lavages. Similar results were not observed in the same model when no E2 was administered to the mice. The FVB mice with no E7 expression which do not develop cervical cancer, did not show comparable changes in the microbiota diversity when E2 was administered during the same period. Normal evolution of the cervical epithelium and microbiota diversity were observed for the FVB mice with no E2 administration. Large changes in the microbiota diversity in fecal samples were not observed suggesting a specific organ effect of E7 expression associated to E2 on the vaginal microbiota.

Laurencia johnstonii extract reverses early lesions in the K14E7HPV16 murine cervical carcinogenesis model

AbstractPersistent infection with high‐risk human papillomavirus (HR‐HPV) is a well‐established risk factor to the development of cervical intraepithelial neoplasia (CIN), a condition that can progress to cervical cancer (CC) a major health problem worldwide. Recently, there has been growing interest in exploring alternative therapies utilizing natural products, among which is the algae species Laurencia johnstonii Setchell & Gardner, 1924 (L. johnstonii), proposed for the management of precancerous lesions. The aim of this work was to determine the effect of an organic extract from L. johnstonii (ELj) in early cervical lesions (CIN 1). These CIN 1 lesions were generated in a murine model expressing the HR‐HPV16 E7 oncoprotein (K14E7HPV transgenic mice) with a single exogenous hormonal stimulus using 17β‐estradiol. The histopathological studies, the determination of cell proliferation and of the apoptotic levels in cervical tissue, showed that, seven doses of ELj (30 mg/kg weight per day diluted in a DMSO‐saline solution [1:7]) lead to recovery the architecture of cervical epithelium. Accordingly, in the transgenic mice it was observed a statistically significant decrease of the PCNA expression levels, a marker of cell proliferation, and a statistically significant increase in the apoptosis levels using Caspase 3 as a marker. In addition, we determined the expression levels of the tumor suppressor miR‐218 and the oncomiRNA miR‐21. Interestingly, our results may suggest that ELj treatment tended to restore the normal expression of both miRNAs as compared with controls being more evident in the non‐transgenic induced mice. Differences of p < 0.05 were considered statistically significant through the whole study. Based on these results, we propose that the use of ELj could be an alternative for the treatment of cervical early lesions.

E7HPV16 Oncogene and 17beta‐Estradiol Stress, Promotes Oncogenic microRNA Expression Patterns, Cell Proliferation and Cervical Intraepithelial Neoplasia 1

ABSTRACTCervical cancer (CC) is the second cause of death by a neoplasia in woman in Mexico. Among the factors that contribute to its development are prolonged infection by a high‐risk HPV type and the use of estrogens. It is well known that diagnosis at early stages is extremely important since, in most cases, progression towards carcinogenesis could be prevented, hence the importance of finding candidates that serve as early biomarkers. Several studies have shown that the expression level of the tumor suppressor miR‐218 is diminished in CC while oncomiR miR‐21 is overexpressed. On the other hand, it has been reported that the Potassium calcium‐activated channel subfamily M alpha 1 (Kcnma1) oncogene, a known target gene of miR‐218, is overexpressed in CC. However, there are few studies on the expression of this oncogene in Cervical Intraepithelial Neoplasia 1 (CIN 1). In this study, the analysis of the K14E7HPV16 carcinogenesis model in young mice (1.5‐month‐old), showed that a single‐dose of 17β‐estradiol (E2) increased both the cell proliferation and the Bcl‐2 oncogene expression, as well as promoted the development of CIN 1. Interestingly, the hormonal stress and the E7 expression, favor the physiological response of the organism in transgenic young mice by decreasing the expression levels of the tumor suppressor miR‐218 and increasing the expression of the Kcnma1 and Bcl‐2 mRNA oncogenes in both, cervical tissue and serum. This work demonstrates the significance of a single E2 stimulation and the expression of the HPV E7 oncoprotein in the early stage of cervical carcinogenesis. In addition, we provide strong evidence about Kcnma1 oncogene as a target gene of miR‐218 and that both could be used as early circulating biomarkers of CC.