MicroRNA-375 Suppresses Extracellular Matrix Degradation and Invadopodial Activity in Head and Neck Squamous Cell Carcinoma

Abstract

Context Head and neck squamous cell carcinoma (HNSCC) is a highly invasive cancer with an association with locoregional recurrence and lymph node metastasis. We have previously reported that low microRNA-375 (miR-375) expression levels correlate with poor patient survival, increased locoregional recurrence, and distant metastasis. Increasing miR-375 expression in HNSCC cell lines to levels found in normal cells results in suppressed invasive properties. HNSCC invasion is mediated in part by invadopodia-associated degradation of the extracellular matrix. Objective To determine whether elevated miR-375 expression in HNSCC cell lines also affects invadopodia formation and activity. Design For evaluation of the matrix degradation properties of the HNSCC lines, an invadopodial matrix degradation assay was used. The total protein levels of invadopodia-associated proteins were measured by Western blot analyses. Immunoprecipitation experiments were conducted to evaluate the tyrosine phosphorylation state of cortactin. Human Protease Arrays were used for the detection of the secreted proteases. Quantitative real time–polymerase chain reaction measurements were used to evaluate the messenger RNA (mRNA) expression of the commonly regulated proteases. Results Increased miR-375 expression in HNSCC cells suppresses extracellular matrix degradation and reduces the number of mature invadopodia. Higher miR-375 expression does not reduce cellular levels of selected invadopodia-associated proteins, nor is tyrosine phosphorylation of cortactin altered. However, HNSCC cells with higher miR-375 expression had significant reductions in the mRNA expression levels and secreted levels of specific proteases. Conclusions MicroRNA-375 regulates invadopodia maturation and function potentially by suppressing the expression and secretion of proteases.

MicroRNA-375 targets PAX6 and inhibits the viability, migration and invasion of human breast cancer MCF-7 cells

“…Deregulated miR-375 has been identified in numerous cancer types, including laryngeal squamous cell carcinoma (23), head and neck squamous cell carcinoma (24), prostate cancer (25), hepatocellular carcinoma (26), lung cancer (27) and breast cancer (28). Wu et al (29) examined the circulating miR profile in patients with breast cancer by deep sequencing all circulating small RNAs.…”

Expression of human papillomavirus oncoproteins E6 and E7 inhibits invadopodia activity but promotes cell migration in HPV‐positive head and neck squamous cell carcinoma cells

“…SCC‐25 and SCC‐61 cells degraded more ECM and formed more degrading and total invadopodia than the SCC‐47 and SCC‐104 cells, while SCC‐1 cells were only significantly greater when compared to SCC‐104 cells (Figure B‐D). These differences are consistent with previous reports of invadopodia activity by these cell lines (except SCC‐104 cells which have not previously been reported to form invadopodia to our knowledge) …”

“…Because HPV + HNSCC has higher rates of metastasis, we first evaluated invadopodia activity in established HPV − and HPV + HNSCC cell lines because the ability to degrade the ECM is an important component of invasion (Figure A). HPV − SCC‐25, SCC‐61, and SCC‐1 cells are frequently used as cell line models for studying invadopodia . HPV + SCC‐47 and SCC‐104 cells are common cell line models for studying the effects of HPV‐16 .…”

miR-375 Affects the Proliferation, Invasion, and Apoptosis of HPV16-Positive Human Cervical Cancer Cells by Targeting IGF-1R

“…17 An increasing number of studies have shown that the biological functions of miRNAs are highly correlated with cervical cancer. 1,2 miR-375 was first discovered in the pancreas; however, recent studies have found that the expression of miR-375 is downregulated in many cancers, such as esophageal squamous cell carcinoma, 18 head and neck cancer, 19 laryngeal squamous cell carcinoma, 20 and oral cancer. 21 Wang et al 12 examined the expression of miR-375 in 170 cervical cancer tissue specimens and 68 normal cervical tissue specimens using stem-loop quantitative PCR and found that compared with the 68 normal tissues, the expression of miR-375 in the cervical cancer tissues was significantly decreased by 4.45-fold.…”