The Effects Of Selenium Compounds On Growth Inhibition Andangiogenesis-relation Factors Regulation In CTM1211

Cancer is an increasing gotcha, which seriously threating human health, breast cancer is one of the most common cancers. As an essential trace element, selenium can against cancer via growth inhibition, immune regulation, apoptosis, antioxidant, angiogenesis and so on, and there’s little research on the specific mechanism, appropriate dose, appropriate form and combination therapy methods of selemium to against cancer. Selenium against cancer depends on the tumor microenvironment regulation, while angiogenesis-related factors plays an important role. VEGF-a and Ang-2, respectively promoting angiogenesis and endothelial cell sprouting, and jointly promote the maturation of tumor blood vessels, while matrix-degrading enzymes is activated at the same time, which make it easier for endothelial cells sprouting and migration, providing a possibility for tumor metastasing and developing; HIF-1a is a oxygen-sensitive transcription factor, compared with normal tissue, HIF-1a get a higher level in tumor, and may be higher when the microenvironment is hypoxia and the tumor is in deterioration. HIF-1a can regulate the survival and self-renewal of cancer stem cells and tumor microenvironment, resulting in futher migration and invasion of tumor. PTEN is a tumor suppressor gene, which can antagonizing PI3 K, transforming phosphoinositide catalysis, inhibiting PI3K-Akt-dependent cell proliferation, migration and angiogenesis. Dogs and humans living in the same environment, it’s practical for us to study the preventive effect selenium has on breast cancer cells. Therefore, we studied the effects of different dose, forms, compatibility of selenium compound have on canine breast cancer cells growth, apoptosis, and angiogenesis-related factors to explore the effective anti-cancer dose, forms and possible mechanisms of selenium. Methods and results are as follows:(1) After intervened by low, medium and high dose of CTX(1,2,4mg/m L), SSE(10,20,40umol/L), MSA(10,20,40umol/L), MSC(200,400,800 umol /L), CTX+SSE(0.5mg/m L+5umol/L,1mg/m L+10umol/L,2mg/m L+20umol/L), CTX+MSA(0.5mg/m L+ 5umol/L,1mg/m L+10umol/L,2mg/m L+20umol/L), CTX+MSC(0.5 mg/m L+100umol/L, 1mg/m L+200umol/L,2mg/m L+400umol/L) for 24 h, 48 h and 72 h, the CTM1211 cells’ viability were measured by MTT. The cell viability of each group were all significantly decreased after intervened by selenium for 48h/72h(P<0.01 or P<0.05). each group showed significantly efficacy- time-dependent(P<0.05) except SSE, but with the increase of the intervene concentration, the cell survival has no significant downward trend; The cell growth inhibition effect of CTX combinated with MSA was significantly enhanced(P<0.01), while CTX combinated with SSE or MSC had no significantly change.(2) After intervened by medium dose of CTX(2mg/m L), SSE(40umol/L), MSA(20umol/L), MSC(400umol/L), CTX+MSA(2mg/m L+20umol/L) for 48h(the same below), the CTM1211 cells’ apoptosis were measured by flow cytometry. The apoptosis rate of each group, especially the group of CTX+MSA, were significantly increased(P <0.01).(3) After intervened by selenium for 48 h, the expression of VEGF-a, PTEN, Ang-2, HIF-1a protein were measured by immunohistochemistry. The expression of VEGF-a, Ang-2 and HIF-1a protein were significantly down-regulated while that of PTEN protein were significantly upregulated by selenium, except for the VEGF-1a protein expression of group SSE(P<0.01 or P<0.05).(4) After intervened by selenium for 48 h, the expression of VEGF-a, PTEN, Ang-2, HIF-1a m RNA were measured by RT-q PCR. The expression of VEGF-a, Ang-2 and HIF-1a m RNA were significantly down-regulated while that of PTEN m RNA were significantly upregulated by selenium, except for the PTEN m RNA expression of group SSE and the HIF-1a m RNA expression of group CTX+MSA(P<0.01 or P<0.05).Conclusions: Three selenium compound(SSE, MSC, MSA) can effectively inhibit CTM1211, MSA has the most significant effect, and its better to compatibility used with CTX, but the increase of dose do not mean the increase of effect; selenium can effectively induce apoptosis of CTM1211, down-regulation the expression of HIF-1a, VEGF-a and Ang-2, up-regulation the expression of PTEN, which has a positive significance on tumor angiogenesis inhibition.