miR-29b enhances prostate cancer cell invasion independently of MMP-2 expression

Author(s)

Ivanovic, Renato F. ^[1] ; Viana, Nayara I. ^[1] ; Morais, Denis R. ^[1] ; Silva, Iran A. ^[1] ; Leite, Katia R. ^[1] ; Pontes-Junior, Jose ^[1] ; Inoue, Gustavo ^[1] ; Nahas, William C. ^{[2, 3]} ; Srougi, Miguel ^[1] ; Reis, Sabrina T. ^[1]

Affiliation

^[1] Univ Sao Paulo, Med Sch, Urol Dept, Lab Med Invest LIM55, Av Dr Arnaldo 455, 2 Floor, Room 2145, BR-01246903 Sao Paulo - Brazil

^[2] ICESP, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Med Sch, Urol Dept, Urooncol Grp, Sao Paulo - Brazil

• Document type: Journal article
• Source: CANCER CELL INTERNATIONAL; v. 18, FEB 5 2018.
• Web of Science Citations: 7

Abstract

Background: The ability to metastasize is one of the most important characteristics of neoplastic cells. An imbalance between the action of some matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs drives the invasion process. Some studies have suggested that MMP-2 is involved in metastasis, while other studies have reported that collagen production by cancer cells might also contribute to motility. However, decreased expression of microRNA-29b (miR-29b), which may control MMP-2 and collagen gene expression, has been shown in prostate cancer (PCa). The objectives of the present study were to clarify whether MMP-2 as well as collagens I and III (encoded by COL1A1 and COL3A1, respectively) are controlled by miR-29b and to determine whether metastasis is altered by this relationship. Methods: PCa DU145 and PC-3 cells were transfected with 100 mu L of OPTI-MEM I containing 100 nmol of miR-29b (or its inhibitor) along with 1.5 mu L of lipofectamine. Positive and negative controls were prepared using the same protocol. MMP-2, COL1A1 and COL3A1 messenger RNA (mRNA) levels were evaluated via real-time polymerase chain reaction (qRT-PCR). For qRT-PCR, 6 x 10(4) cells were used. Invasion studies were conducted with Matrigel assays, which simulate invasion of the extracellular matrix by neoplastic cells. After transfection of 3 x 10(4) cells, invasion was allowed to proceed for 48 h. Invasive cells were counted under an optical microscope. Each experiment was performed in triplicate. Results: MMP-2 mRNA was not expressed in DU145 cells after transfection with miR-29b. After transfection of cells with the miR-29b inhibitor, COL1A1 (p = 0.02) and COL3A1 (p = 0.06) mRNA expression was increased in DU145 cells, and a large number of transfected DU145 and PC3 cells invaded the Matrigel membrane. Conclusions: In vitro studies showed that reducing the amount of miR-29b may lead to higher PCa cell invasion via a process that is independent of MMP-2. Collagen expression, controlled by miR-29b, may facilitate this motility process. Thus, the present study suggests that collagen production plays an active role in metastasis control and restoration of miR-29b levels may decrease metastasis. Altogether, these findings support further exploration of drug therapy targeting this aspect of the metastasis circuit. (AU)

• FAPESP's process: 12/21833-8 - Analysis of miRNAs involved in regulation of MMP2 and MMP9 and its implication of this regulators and regulating the process of cell migration and invasion of the prostate adenocarcinoma
• Grantee: Sabrina Thalita dos Reis Faria
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/00845-6 - Analysis of the miRNAs involved in the regulation of MMP2 and MMP9 and regulators, and the implication of this adjustment in cell invasion in prostate adenocarcinoma process: in vivo and in vitro studies
• Grantee: Renato Fidelis Ivanovic
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)