Novel biomarkers used for early diagnosis and tyrosine kinase inhibitors as targeted therapies in colorectal cancer

Colorectal cancer (CRC) is the third most common and second most lethal type of cancer worldwide, presenting major health risks as well as economic costs to both people and society. CRC survival chances are significantly higher if the cancer is diagnosed and treated early. With the development of molecular biology, numerous initiatives have been undertaken to identify novel biomarkers for the early diagnosis of CRC. Pathological disorders can be diagnosed at a lower cost with the help of biomarkers, which can be detected in stool, blood, and tissue samples. Several lines of evidence suggest that the gut microbiota could be used as a biomarker for CRC screening and treatment. CRC treatment choices include surgical resection, chemotherapy, immunotherapy, gene therapy, and combination therapies. Targeted therapies are a relatively new and promising modality of treatment that has been shown to increase patients' overall survival (OS) rates and can inhibit cancer cell development. Several small-molecule tyrosine kinase inhibitors (TKIs) are being investigated as potential treatments due to our increasing awareness of CRC's molecular causes and oncogenic signaling. These compounds may inhibit critical enzymes in controlling signaling pathways, which are crucial for CRC cells' development, differentiation, proliferation, and survival. On the other hand, only one of the approximately 42 TKIs that demonstrated anti-tumor effects in pre-clinical studies has been licensed for clinical usage in CRC. A significant knowledge gap exists when bringing these tailored medicines into the clinic. As a result, the emphasis of this review is placed on recently discovered biomarkers for early diagnosis as well as tyrosine kinase inhibitors as possible therapy options for CRC.

The diagnostic significance of CDH17-positive circulating tumor cells in patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer deaths in Hong Kong. We tested the hypothesis that circulating tumor cell (CTC) analysis by ARB101 antibody could be used as a tool for CRC detection, progression, and therapy response.

RESEARCH METHODS

ARB101 antibody was used for investigation of CDH17 expression in formalin-fixed, paraffin-embedded (FFPE) tissue sections and circulating tumor cells (CTCs) of CRC patients.

RESULTS

Using ARB101, highest sensitivity was observed in 98/100 (98%) colorectal cancer tissue compared to 72/100 gastric cancer (72%) and 27/32 pancreatic cancer (84%). Immunoreactivity of CDH17 was significantly higher in distant metastatic (tumor-node-metastasis [TNM] stage IV) than non-distant metastatic (TNM stage I to III) CRC. ARB101 antibody also manifested the higher sensitivity than c-erbB2 (8%) and epidermal growth factor receptor (EGFR)-targeting antibodies (37%) with the significance (p < 0.0001). ARB101 positive CTCs were detected in 64/83 (77%) TNM stage I to IV CRC patients. Furthermore, ARB101 positive CTCs detected in TNM stage I to III CRC patients before and after surgical operation are statistically significant (p < 0.0001).

CONCLUSIONS

CTC detection by ARB101 antibody could serve as a potential non-invasive approach for CRC detection, progression, and monitoring of treatment response.

Identification of a 15 DNA Damage Repair-Related Gene Signature as a Prognostic Predictor for Lung Adenocarcinoma

BACKGROUND

Lung Adenocarcinoma (LUAD) is a common malignancy with a poor prognosis due to the lack of predictive markers. DNA Damage Repair (DDR)-related genes are closely related to cancer progression and treatment.

INTRODUCTION

To identify a reliable DDR-related gene signature as an independent predictor of LUAD.

METHODS

DDR-related genes were obtained using combined analysis of TCGA-LUAD data and literature information, followed by the identification of DDR-related prognostic genes. The DDR-related molecular subtypes were then screened, followed by Kaplan-Meier analysis, feature gene identification, and pathway enrichment analysis of each subtype. Moreover, Cox and LASSO regression analyses were performed for the feature genes of each subtype to construct a prognostic model. The clinical utility of the prognostic model was confirmed using the validation dataset GSE72094 and nomogram analysis.

RESULTS

Eight DDR-related prognostic genes were identified from 31 DDR-related genes. Using consensus cluster analysis, three molecular subtypes were screened. Cluster 2 had the best prognosis, while cluster 3 had the worst. Compared to cluster 2, clusters 1 and 3 consisted of more stage 3 - 4, T2-T4, male, and older samples. The feature genes of clusters 1, 2, and 3 were mainly enriched in the cell cycle, arachidonic acid metabolism, and ribosomes. Furthermore, a 15-feature gene signature was identified for improving the prognosis of LUAD patients.

CONCLUSION

The 15 DDR-related feature gene signature is an independent and powerful prognostic biomarker for LUAD that may improve risk classification and provide supplementary information for a more accurate evaluation and personalized treatment.