cytochromes-c1 and Carcinoma

Cytochrome c1 (CYC1) is a heme-containing subunit of mitochondria complex III and is mainly involved in cellular energy production. A recent study has demonstrated that CYC1 was overexpressed in breast carcinoma tissues and induced proliferation, migration and invasion of estrogen receptor (ER)-negative breast carcinoma cells. However, the clinical significance of CYC1 protein remains largely unclear in invasive breast carcinoma, and biological functions of CYC1 have not been reported in ER-positive breast carcinoma cells.. We immunolocalized CYC1 in 172 invasive breast carcinomas and evaluated its clinical significance according to the ER-status. Subsequently, we examined the effects of CYC1 on proliferation, glycolysis and chemosensitivity to paclitaxel, which is one of the most common chemotherapeutic agents in breast cancer, in ER-positive breast carcinoma cells (MCF7 and T47D).. CYC1 immunoreactivity was detected in 47% of ER-positive cases and 30% of ER-negative cases. Immunohistochemical CYC1 status was inversely associated with Ki67 in ER-positive cases, and it was a significantly favorable prognostic factor for both disease-free and breast cancer-specific survival of the patients. On the other hand, no significant association was detected between CYC1 status and clinicopathological factors in ER-negative cases. In in vitro experiments, MCF7 and T47D cells transfected specific siRNA for CYC1 significantly increased cell proliferation activity, L-lactate production and cell viability after paclitaxel treatment.. These results suggest that CYC1 inhibits cell proliferation, glycolytic activity and increases chemosensitivity to paclitaxel in ER-positive breast carcinoma cells and that CYC1 status is a potent favorable prognostic factor in ER-positive breast cancer patients.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Breast; Breast Neoplasms; Carcinoma; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cytochromes c1; Disease-Free Survival; Estrogen Receptor alpha; Female; Glycolysis; Humans; Ki-67 Antigen; Lactic Acid; MCF-7 Cells; Middle Aged; Paclitaxel; Phenotype; Prognosis; RNA, Small Interfering; Time Factors

To analyze the expression of Cyc1 in nasopharyngeal carcinoma (NPC) and evaluate the interfering efficiency of a lentivirus interfering vector targeting Cyc1 in NPC cells.. Microarray technique was used to examine the expression of Cyc1 in NPC tissues. Real-time PCR was utilized to confirm the high expression of Cyc1 in NPC tissues and NPC cell lines. The recombinant Cyc1 shRNA-expressing plasmid (pLentiU6/Cyc1-shRNA) was stably transfected into NPC cells, and the interfering efficiency against Cyc1 was evaluated by quantitative RT-PCR.. The result of microarray showed that Cyc1 was highly expressed in NPC tissues compared to noncancerous nasopharyngeal tissues, as confirmed by Real-time PCR. All of the 8 NPC cells showed a high expression of Cyc1, among which 5-8F cells showed the highest expression. Sequence analysis indicated that the recombinant plasmid pLentiU6/Cyc1-shRNA was successfully constructed and could significantly and stably suppress the expression of Cyc1 in NPC cells.. Cyc1 is highly expressed in NPC cells. The lentivirus vector constructed can markedly inhibit the expression of Cyc1 in NPC cells, which provides assistance in the investigation of the function and molecular mechanism of Cyc1 in NPC.

Topics: Carcinoma; Cell Line, Tumor; Cytochromes c1; Genetic Vectors; Humans; Lentivirus; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Oligonucleotide Array Sequence Analysis; Plasmids; RNA, Small Interfering