MDA MB 231 cells overexpressing CTGF show a rise in autophagy and oxidative worry. To assess in the event the role of CTGF in tumorigenesis is compartment specific, we overex pressed CTGF in MDA MB 231 cells. We up coming inves tigated whether CTGF also induces autophagy mitophagy in epithelial cancer cells. Immunoblot analysis demonstrated that MDA MB 231 cells overexpressing CTGF display the upregula tion of numerous autophagy mitophagy markers under basal con dition or upon nutrient starvation, indicating that CTGF can activate autophagy also in breast cancer epithelial cells. Having said that, no alterations in L lactate production had been observed in MDA MB 231 cells overexpressing CTGF. Due to the fact we demonstrated that CTGF induces autophagy in fibro blasts via HIF one, we evaluated when the very same mechanism operates in MDA MB 231 cells. Although HIF one expression is only slightly elevated in MDA MB 231 cells overexpressing CTGF, a significant 20% enhance in ROS production in MDA MB 231 cells overexpressing CTGF was observed as in contrast with manage cells.
For that reason, we think that the CTGF induction of autophagy also is dependent upon enhanced oxi dative stress in breast cancer cells. Hence, we conclude that CTGF induces an autophagic plan in each cell forms, fibroblasts and MDA MB 231 cells, by inducing oxidative stress, HIF 1 activa tion plus a pseudo hypoxic phenotype. CTGF overexpression isn’t going to modulate the expression of senescence markers in breast cancer cells. As a way to below selelck kinase inhibitor stand if CTGF activate precisely the same processes activated in fibroblasts in epithelial breast cancer cells, we evaluated the expression of proteins concerned in cell cycle regulation. Figure 9 demonstrates that CTGF overexpression in MDA MB 231 cells isn’t going to induce markers of senescence. Certainly, no substantial modifications were detected in p16, p19 and Cyclin D1 expres sion levels, whereas p21 was undetectable. CTGF overexpression in breast cancer cells inhibits Torcetrapib tumor growth.
To investigate the effects of CTGF overexpression in breast cancer cells in vivo, CTGF MDA MB 231 and manage MDA MB 231 cells had been injected into the flanks of athymic nude mice. Surprisingly, Figure 10A exhibits that following 3 weeks, CTGF overexpression caused a virtually 3 fold reduction in tumor development. Also on this context, we did not detect any differences in tumor neo vascularization, as assessed by quantification of CD31 constructive vessels. These final results clearly indicate that CTGF plays
a compartment and cell variety certain function dur ing tumor formation and exerts opposing effects depending on which cell variety expresses it. Last but not least, to evaluate the part of extracellular matrix deposition in CTGF mediated tumorigenesis, we evaluated the expression of Style Collagen and Tenascin C in MDA MB 231 tumor xeno grafts.