Immunoexpression of TS, p53, COX2, EGFR, MSH6 and MLH1 biomarkers and its correlation with degree of differentiation, tumor staging and prognostic factors in colorectal adenocarcinoma: a retrospective longitudinal study

PTGS2 Over-Expression: A Colorectal Carcinoma Initiator not an Invasive Factor

BACKGROUND

Cyclooxygenase-2 (COX-2) main product is Prostaglandin E2 (PGE2) which cause mitogenesis and inflammation. COX-2 is the product of prostaglandin-endoperoxide synthase 2 (PTGS2) gene expression. COX-2 dysregulation can cause angiogenesis, differentiation, and promotion of cancer and its suppression related to control of the tumor's size, number, and cell shape. This study focused on the association of COX-2 expression with colorectal carcinoma (CRC) among Iranian patients on mRNA level and in the Cancer Genome Atlas Program (TCGA) colon and rectum RNAseq dataset, and its relation with pathological features.

METHODS

PTGS2 expression was assayed by quantitative-PCR method from 90 tissue samples collected from 45 participants. The control samples come from the non-tumor area of the same patients. The data analyzed based on ΔΔCq. The PTGS2-RNAseq data extracted and analyzed by UCSC Xena browser, and its association assessed the occurrence of CRC and invasive-features.

RESULTS

PTGS2 showed very significant over-expression in tumor tissues (p< 0.0001) with an N-fold expression of 2.25. But, there was not any significant association between PTGS2 and CRC invasive-pathological features such as Lymphatic, vascular and perineural invasion, the Grades of cancer, and Pathologic-M in both parts of this study.

CONCLUSION

The increase in PTGS2 is related to the occurrence of CRC among patient samples. But in both part of this study, PTGS2 is not an invasive factor, and it does not affect the cell differentiation of tumors and metastasis. Based on the high N-fold for patient samples, it can be a strong candidate as a CRC initiator biomarker.

Role of Inflammation in the Development of Colorectal Cancer

Chronic inflammation can lead to the development of many diseases, including cancer. Inflammatory bowel disease (IBD) that includes both ulcerative colitis (UC) and Crohnmp's disease (CD) are risk factors for the development of colorectal cancer (CRC). Many cytokines produced primarily by the gut immune cells either during or in response to localized inflammation in the colon and rectum are known to stimulate the complex interactions between the different cell types in the gut environment resulting in acute inflammation. Subsequently, chronic inflammation, together with genetic and epigenetic changes, have been shown to lead to the development and progression of CRC. Various cell types present in the colon, such as enterocytes, Paneth cells, goblet cells, and macrophages, express receptors for inflammatory cytokines and respond to tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, and other cytokines. Among the several cytokines produced, TNF-α and IL-1β are the key pro-inflammatory molecules that play critical roles in the development of CRC. The current review is intended to consolidate the published findings to focus on the role of pro-inflammatory cytokines, namely TNF-α and IL-1β, on inflammation (and the altered immune response) in the gut, to better understand the development of CRC in IBD, using various experimental model systems, preclinical and clinical studies. Moreover, this review also highlights the current therapeutic strategies available (monotherapy and combination therapy) to alleviate the symptoms or treat inflammation-associated CRC by using monoclonal antibodies or aptamers to block pro-inflammatory molecules, inhibitors of tyrosine kinases in the inflammatory signaling cascade, competitive inhibitors of pro-inflammatory molecules, and the nucleic acid drugs like small activating RNAs (saRNAs) or microRNA (miRNA) mimics to activate tumor suppressor or repress oncogene/pro-inflammatory cytokine gene expression.

Epidemiology characteristics of ethnic minority colorectal cancer in Yunnan in Southwestern China

BACKGROUND

Colorectal cancer (CRC) is one of the world's deadliest cancers, and its mortality rate has been on the rise in China. Yunnan is a region with a higher concentration of ethnic minorities. CRC affects many people from ethnic minority groups, which differ from Han in terms of their age and gender compositions.

METHODS

We collected samples from 1,016 cases of CRC patients along with their case files at Yunnan Provincial Cancer Hospital from the period between January 2013 and December 2018.

RESULTS

In total, 7.1% (n=72) of all lung cancer cases diagnosed from 2013 to 2018 in Yunnan Provincial Cancer Hospital occurred in patients 40 years old or younger, 44% (n=447) were 40 to 60 years old, and 48.9% (n=497) were 60 years old or above. The composition ratio of CRC patients in the different age groups differed significantly and enhanced significantly with age, with a statistical significance of P<0.05. A total of 33.6% (n=38) of 113 minority patients and 16.8% (n=152) of 903 Han patients reported a history of smoking, and 23.0% (n=26) of 113 minority patients and 14.6% (n=132) of Han patients had a history of drinking. Long-term smoking and drinking are significantly associated with the incidence of CRC, and this was more significant among ethnic minorities (P<0.05).

CONCLUSIONS

The high incidence of CRC in Yunnan is strongly related to patients' lifestyles, and diet should be a core focus of efforts to prevent and treat CRC. Early screening and regular check for common tumor markers can also help to reduce the incidence of CRC and provide a basis for improvements in CRC treatment and prognosis in Yunnan.