Expression and Polymorphism of TSLP/TSLP Receptors as Potential Diagnostic Markers of Colorectal Cancer Progression

Molecular pathology of colorectal cancer: The Saudi situation in perspective

Colorectal cancer (CRC) is one of the most common cancers worldwide, and one of the most common causes of cancer deaths. In recent times, significant advancements have been made in elucidating the molecular alterations of the disease, and the results have been an improved understanding of CRC biology, as well as the discovery of biomarkers of diagnostic, prognostic, and therapeutic significance. In this review, an evaluation is carried out of the molecular pathology research of CRC emanating from Saudi Arabia. The verdict is that the data on the molecular alterations in CRC from Saudi patients is at best modest. This dearth of molecular pathology data is aptly reflected in the paucity of molecular markers recommended for testing by the Saudi National Cancer Centre guidelines for CRC management. Large scale multi-institutional and multiregional translational studies are required to generate molecular data that would inform diagnostic, prognostic, and risk-stratification guidelines for Saudi CRC patients.

A pairwise immune gene model for predicting overall survival and stratifying subtypes of colon adenocarcinoma

OBJECTIVES

There is increasing evidence for a close correlation between risk stratification, prognosis and the immune environment in colon adenocarcinoma (COAD). However, the efficacy of immunotherapy is different among different patients with COAD. Therefore, the current work tends to use immune-related gene to develop a gene-pair model to evaluate the COAD prognosis, and to develop a new method for risk stratification of COAD, which is conducive to better predict the immunotherapy effect of patients.

METHODS

Specifically, from the TCGA and GEO (GSE14333 and GSE39582) databases, we first collected gene expression profiles, associated survival follow-up information of COAD patients. Through systematic bioinformatics analysis, we established a prognosis-related model of colon cancer with three pairs of "immune gene pairs", with uni- and multivariate and lasso cox regression analyses verifying the model stability. Most immune cells showed markedly different levels of infiltration between the two risk subgroups calculated by the model. More, single-cell RNA-seq analyses were also performed to validate the selected genes in the immune gene-pair model.

RESULTS

A prognosis-related model of colon cancer with three pairs of "immune gene pairs" were built and validated by several datasets. The analysis of immune landscape of COAD revealed that low-risk subgroup obtained by the prognosis-related model for COAD can be further divided into three subclusters with different prognosis. Then, we applied the Tumor online Prognostic analyses Platform (ToPP) to construct a prognostic model using these five genes. Results show that APOD, ISG20 and STC2 are risk factors, while CXCL9 and IL7R are protection factors. We also found that only the five-gene model could also predict the prognosis of COAD patients, indicating the robustness of the gene-pair model. Among the five genes, including CXCL9, APOD, STC2, ISG20, and IL7R, in the gene-pair model, single-cell RNA sequencing reveals the high expression of CXCL9 and IL7R in inflammatory macrophages. Using cell-cell interaction and trajectory analysis, data indicate that CXCL9+/IL7R+ pro-inflammatory macrophages were capable of secreting and activating more anti-tumor pathways than CXCL9-/IL7R- pro-inflammatory macrophages.

CONCLUSIONS

In short, we have successfully developed an "immune gene pair" related model that can judge the prognostic status of patients with COAD and may contribute to risk stratification and evaluate potential beneficiaries of immunotherapy, providing new ideas for the anti-COAD management and therapy.

A Significant Increasing Risk Association between Cigarette Smoking and XPA and XPC Genes Polymorphisms

Cigarette smoking (CS) is a major cause of various serious diseases due to tobacco chemicals. There is evidence suggesting that CS has been linked with the DNA damage repair system, as it can affect genomic stability, inducing genetic changes in the genes involved in the repair system, specifically the nucleotide excision repair (NER) pathway, affecting the function and/or regulation of these genes. Single nucleotide polymorphism (SNP), along with CS, can affect the work of the NER pathway and, therefore, could lead to different diseases. This study explored the association of four SNPs in both XPA and XPC genes with CS in the Saudi population. The Taq Man genotyping assay was used for 220 healthy non-smokers (control) and 201 healthy smokers to evaluate four SNPs in the XPA gene named rs10817938, rs1800975, rs3176751, and rs3176752 and four SNPs in the XPC gene called rs1870134, rs2228000, rs2228001, and rs2607775. In the XPA gene, SNP rs3176751 showed a high-risk association with CS-induced diseases with all clinical parameters, including CS duration, CS intensity, gender, and age of smokers. On the other hand, SNP rs1800975 showed a statistically significant low-risk association with all clinical parameters. In addition, rs10817938 showed a high-risk association only with long-term smokers and a low-risk association only with younger smokers. A low-risk association was found in SNP rs3176752 with older smokers. In the XPC gene, SNP rs2228001 showed a low-risk association only with female smokers. SNP rs2607775 revealed a statistically significant low-risk association with CS-induced diseases, concerning all parameters, except for male smokers. However, SNP rs2228000 and rs1870134 showed no association with CS. Overall, the study results demonstrated possible significant associations (effector/and protector) between CS and SNPs polymorphisms in DNA repair genes, such as XPA and XPC, except for rs2228000 and rs1870134 polymorphisms.

Role of thymic stromal lymphopoietin in allergy and beyond

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine that acts on multiple cell lineages, including dendritic cells, T cells, B cells, neutrophils, mast cells, eosinophils and innate lymphoid cells, affecting their maturation, survival and recruitment. It is best known for its role in promoting type 2 immune responses such as in allergic diseases and, in 2021, a monoclonal antibody targeting TSLP was approved for the treatment of severe asthma. However, it is now clear that TSLP has many other important roles in a variety of settings. Indeed, several genetic variants for TSLP are linked to disease severity, and chromosomal alterations in TSLP are common in certain cancers, indicating important roles of TSLP in disease. In this Review, we discuss recent advances in TSLP biology, highlighting how it regulates the tissue environment not only in allergic disease but also in infectious diseases, inflammatory diseases and cancer. Encouragingly, therapies targeting the TSLP pathway are being actively pursued for several diseases.

Molecular and cellular pathways in colorectal cancer: apoptosis, autophagy and inflammation as key players

BACKGROUND

Colorectal carcinogenesis (CRC) is one of the most aggressive forms of cancer, particularly in developing countries. It accounts for the second and third-highest reason for cancer-induced lethality in women and men respectively. CRC involves genetic and epigenetic modifications in colonic epithelium, leading to colon adenocarcinoma. The current review highlights the pathogenic mechanisms and multifactorial etiology of CRC, influenced by apoptosis, inflammation, and autophagy pathways.

METHODS

We have carried out a selective literature review on mechanisms contributing to the pathogenesis of CRC.

RESULTS

Resistance to senescence and apoptosis of the mesenchymal cells, which play a key role in intestinal organogenesis, morphogenesis and homeostasis, appears important for sporadic CRC. Additionally, inflammation-associated tumorigenesis is a key incident in CRC, supported by immune disruptors, adaptive and innate immune traits, environmental factors, etc. involving oxidative stress, DNA damage and epigenetic modulations. The self-digesting mechanism, autophagy, also plays a twin role in CRC through the participation of LC3/LC3-II, Beclin-1, ATG5, other autophagy proteins, and Inflammatory Bowel Disease (IBD) susceptibility genes. It facilitates the promotion of effective surveillance pathways and stimulates the generation of malignant tumor cells. The autophagy and apoptotic pathways undergo synergistic or antagonistic interactions in CRC and bear a critical association with IBD that results from the pro-neoplastic effects of persistent intestinal inflammation. Conversely, pro-inflammatory factors stimulate tumor growth and angiogenesis and inhibit apoptosis, suppressing anti-tumor activities.

CONCLUSION

Hence, research attempts for the development of potential therapies for CRC are in progress, primarily based on combinatorial approaches targeting apoptosis, inflammation, and autophagy.