RESUMO
Chromodomain helicase DNA binding protein 5 (CHD5) acts as a tumor suppressor in various types of cancer and belongs to CHD protein family. However, no prognostic role for CHD5 has yet been indicated in colorectal cancer. Therefore, the aim of this study was to investigate a possible association between CHD5 expression and colorectal cancer prognosis. Furthermore, immunochemistry was used to investigate CHD5 expression in 310 CRC tissue specimens. Expression of CHD5 significantly positively correlated with the lymphatic metastasis (P=0.007). The prognostic value of CHD5 in relation to overall survival was analyzed by Kaplan-Meier analysis and Cox proportional hazard models. The mean and medium follow-up times after surgery were 5.5 and 6.6 years, respectively. A total of 150 patients died during the 13 years of follow-up in the survey period. We also demonstrated that overall survival was poor in CRC patients with low expression of CHD5 (P=0.003). Accordingly, multivariate analysis identified low CHD5 expression as an independent risk factor (P=0.014), especially in elderly patients or those with late stage cancers. We suggest that CHD5 could serve as an independent prognostic biomarker for colorectal patients. This finding also should be verified by other research groups.
RESUMO
Reprogrammed metabolism is a hallmark of cancer cells. Pyruvate kinase isozyme type M2 (PKM2), which is frequently up-regulated in multiple human malignancies, has been demonstrated to play a critical function in glucose metabolism, gene transcription and tumorigenesis. However, limited knowledge is known about the expression pattern and prognostic value of PKM2 in colorectal cancer (CRC). In this study, we first observed that the mRNA level of PKM2 is commonly up-regulated in CRC tissues compared with their normal counterparts as demonstrated by data derived from Oncomine database. Similar results were also found in 32 paired CRC tumor and non-tumor specimens in our cohort and 4 CRC cell lines. Furthermore, by a large scale of immunohistochemical analysis in a tissue microarray containing 345 cases of CRC specimens, we demonstrated that the protein expression of PKM2 expression is up-regulated in 79.4% (274/345) samples detected and elevated PKM2 expression is closely correlated with enhanced TNM stage and higher serum CEA level. Meanwhile, Kaplan-Meier survival analysis showed that CRC patients with a higher PKM2 expression have a poorer clinical outcome than those with a lower PKM2 expression. Multivariate Cox regression analysis revealed that PKM2 and TNM stage are two independent prognostic factors for overall survival rate of CRC patients. Taken together, our studies reveal the prognostic value of PKM2 in CRC and support that PKM2 may act as a molecular target for CRC treatment.
