Phosphoglycerate dehydrogenase (PHGDH) plays an essential role in cancer-specific metabolic reprogramming. It has been reported as a putative metabolic oncogene in several types of human malignant tumors, such as breast cancer and melanoma. To date, PHGDH expression in colorectal cancer (CRC) as well as its association with clinicopathological characteristics and prognostic implication remain undetermined. In this study, we determined the PHGDH protein expression using tissue microarray immunohistochemistry (TMA-IHC) on 193 pairs of formalin-fixed, paraffin-embedded specimens of CRC and adjacent tissues, 25 chronic colitis, 41 low-, and 19 high-grade intraepithelial neoplasia specimens, and we also determined PHGDH mRNA level using quantitative reverse transcription PCR (qRT-PCR) on additional 23 pairs of fresh CRC tissues and adjacent tissues. We found that both PHGDH mRNA and protein was highly expressed in tumor tissues in comparison with matched adjacent non-tumor tissues, and high PHGDH protein expression was correlated with advanced TNM stage (P = .038) and larger tumor (P = .001). Multivariate Cox regression analysis showed that PHGDH protein expression (HR = 2.285, 95% CI = 1.18 to 4.41, P = .014), tumor differentiation (HR = .307, 95% CI = .154 to 0.609, P = .001), and TNM stage (HR = 1.791, 95% CI = 1.125 to 2.85, P = .014) were independent prognostic factors in CRC. Kaplan-Meier survival curves and log rank test showed that high PHGDH protein expression contributed to poor outcome in CRC patients (P < .001). In conclusion, these results suggest that assessment of PHGDH expression could be useful in identifying a high-risk subgroup of CRC.

Background: Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract. According to the research of circular RNAs in the CRC field, compared with linear RNAs, circular RNAs are a special type of noncoding RNA that are covalently closed circular structures, which have no 5' cap structure and 3' polyA tail and are not affected by RNA exonuclease and actinomycin D.Biological functions: Notably, circular RNAs have a high degree of stability and potential effect on gene regulation. Meanwhile, circular RNAs are involved in the sponge action of microRNAs and mediate protein translation and direct binding, alternative splicing, and histone modification.Relationships with CRC: Studies have shown that circular RNAs are related to the proliferation, invasion, recurrence, metastasis, ferroptosis, apoptosis, and chemotherapy resistance of CRC.Conclusions: This article provides a brief review based on the source, structural characteristics, mechanisms, biological functions of circular RNAs, and the relationships between CRC.

Small nucleolar RNAs (snoRNAs) are a class of non-coding RNAs that play indispensable roles in cancers, including colorectal cancer (CRC). However, the role of SNORD1C in CRC is unclear. In the current study, SNORD1C expression was measured in CRC tissues using quantitative real-time PCR. A series of in vivo and in vitro experiments were performed to examine the functional role of SNORD1C in CRC. Quantitative real-time PCR, western blotting, sphere formation assay, and chemotherapy resistance analysis were conducted to illustrate the SNORD1C molecular mechanism. SNORD1C was upregulated in CRC and that high SNORD1C expression was related to poor prognosis. After knocking down SNORD1C in CRC cell lines, cell proliferation, colony formation, cell migration, and invasion were alleviated, while apoptosis was increased. Transcriptional RNA-sequencing analysis revealed that following SNORD1C knockdown, β-catenin was downregulated, as was the transcription factor TCF7, which inhibited the Wnt/β-catenin pathway. Meanwhile, levels of the stem cell-related factors were reduced, diminishing cell stemness and tumorigenesis. Our findings suggest that SNORD1C functions via the Wnt/β-catenin pathway to enhance cancer cell stemness in CRC and could be a predictive biomarker for the prognosis ad aggressiveness of this malignancy. Additionally, targeting SNORD1C may be a novel therapeutic strategy for CRC.