HPV16 Oncoproteins Induce MMPs/RECK-TIMP-2 Imbalance in Primary Keratinocytes: Possible Implications in Cervical Carcinogenesis

Abstract

Cervical cancer is the third most common cancer in women worldwide. Persistent infection with high-risk HPV types, principally HPV16 and 18 is the main risk factor for the development of this malignancy. However, the onset of invasive tumor occurs many years after initial exposure in a minority of infected women. This suggests that other factors beyond viral infection are necessary for tumor establishment and progression. Tumor progression is characterized by an increase in secretion and activation of matrix metalloproteinases (MMPs) produced by either the tumor cells themselves or tumor-associated fibroblasts or macrophages. Increased MMPs expression, including MMP-2, MMP-9 and MT1-MMP, has been observed during cervical carcinoma progression. These proteins have been associated with degradation of ECM components, tumor invasion, metastasis and recurrence. However, few studies have evaluated the interplay between HPV infection and the expression and activity of MMPs and their regulators in cervical cancer. We analyzed the effect of HPV16 oncoproteins on the expression and activity of MMP-2, MMP-9, MT1-MMP, and their inhibitors TIMP-2 and RECK in cultures of human keratinocytes. We observed that E7 expression is associated with increased pro-MMP-9 activity in the epithelial component of organotypic cultures, while E6 and E7 oncoproteins co-expression down-regulates RECK and TIMP-2 levels in organotypic and monolayers cultures. Finally, a study conducted in human cervical tissues showed a decrease in RECK expression levels in precancer and cancer lesions. Our results indicate that HPV oncoproteins promote MMPs/RECK-TIMP-2 imbalance which may be involved in HPV-associated lesions outcome.

MMP-9/RECK Imbalance: A Mechanism Associated with High-Grade Cervical Lesions and Genital Infection by Human Papillomavirus and Chlamydia trachomatis

“…In that model, the authors hypothesized that TIMP-2, but not RECK, is involved in MMP inhibition. However, in the present study, data from clinical samples evidenced an imbalance between MMP and RECK, which has already been shown in other human cancers (24)(25)(26) and in organotypic epithelial cultures with HPV-infected keratinocytes (11).…”

“…To analyze MMPs status in a system that reproduces in vivo conditions, we have previously developed organotypic epithelial cultures with keratinocytes expressing HPV 16 oncoproteins. We have demonstrated that HPV 16 E7 induces pro-MMP-9 activity, and that E6 and E7 coexpression downregulates RECK protein levels (11). This latter study also demonstrated that, even in small number of clinical samples, there is an inverse correlation between RECK expression and degree of cervical lesion.…”

“…Ghosh and colleagues (28) investigated the gelatinolytic activity of matrix MMP-2 and MMP-9 in preinvasive and invasive carcinoma of the uterine cervix and concluded that both MMP-2 and MMP-9 have a role in cancer progression and remodeling of the ectocervix. Furthermore, a study conducted in cervical biopsies showed a decrease in RECK expression in preneoplasic and neoplasic lesions (11).…”

“…This test uses target-DNA amplification by PCR and nucleic acids hybridization, detecting 37 types of low-and high-risk HPVs: HPV 6,11,16,18,26,31,33,35,39,40, …”

MicroRNA-106a promotes cell migration and invasion by targeting tissue inhibitor of matrix metalloproteinase 2 in cervical cancer

“…MMPs, especially MMP2 and MMP9, are able to degrade ECM to promote endothelial cell migration and trigger an angiogenic switch by releasing VEGF from ECM (31). TIMPs are specific inhibitors of MMP2 and MMP9, which were decreased in CC (32,33). Our results revealed that TIMP2 abolished the stimulatory effect of miR-106a on CC cells.…”