ABSTRACT
Metastatic colorectal cancer (mCRC) currently lacks reliable biomarkers for precision medicine, particularly for chemotherapy-based treatments. This study examines the behavior of 11 CXC chemokines in the blood of 104 mCRC patients undergoing first-line oxaliplatin-based treatment to pinpoint predictive and prognostic markers. Serum samples were collected before treatment, at response evaluation (EVAR), and at disease progression or last follow-up. Chemokines were assessed in all samples using a Luminex® custom panel. CXCL13 levels increased at EVAR in responders, while in non-responders it decreased. Increasing levels of CXCL13 at EVAR, independently correlated with improved progression-free survival (PFS) and overall survival (OS). Nanostring® analysis in primary tumor samples showed CXCL13 gene expression's positive correlation not only with gene profiles related to an immunogenic tumor microenvironment, increased B cells and T cells (mainly CD8+) but also with extended OS. In silico analysis using RNAseq data from liver metastases treated or not with neoadjuvant oxaliplatin-based combinations, and deconvolution analysis using the MCP-counter algorithm, confirmed CXCL13 gene expression's association with increased immune infiltration, improved OS, and Tertiary Lymphoid Structures (TLSs) gene signatures, especially in neoadjuvant-treated patients. CXCL13 analysis in serum from 36 oxaliplatin-treated patients from the METIMMOX study control arm, reported similar findings. In conclusion, the increase of CXCL13 levels in peripheral blood and its association with the formation of TLSs within the metastatic lesions, emerges as a potential biomarker indicative of the therapeutic efficacy in mCRC patients undergoing oxaliplatin-based treatment.
ABSTRACT
In recent years, an increasing number of studies have shown that elevated expression of cyclin dependent kinase (Cdk5) contributes to the oncogenic initiation and progression of many types of cancers. In this study, we investigated the expression pattern of Cdk5 in colorectal cancer (CRC) cell lines and in a large number of tumor samples in order to evaluate its relevance in this pathogenesis and possible use as a prognostic marker. We found that Cdk5 is highly expressed and activated in CRC cell lines and that silencing of the kinase decreases their migration ability. In tumor tissues, Cdk5 is overexpressed compared to normal tissues due to a copy number gain. In patients with localized disease, we found that high Cdk5 levels correlate with poor prognosis, while in the metastatic setting, this was only the case for patients receiving an oxaliplatin-based treatment. When exploring the Cdk5 levels in the consensus molecular subtypes (CMS), we found the lowest levels in subtype 1, where high Cdk5 again was associated with a poorer prognosis. In conclusion, we confirm that Cdk5 is involved in CRC and disease progression and that it could serve as a prognostic and predictive biomarker in this disease.
ABSTRACT
Colorectal cancer (CRC) is the third most common cancer in men and the second most common cancer in women, worldwide. In the early stages of the disease, biomarkers predicting early relapse would improve survival rates. In metastatic patients, the use of predictive biomarkers could potentially result in more personalized treatments and better outcomes. The CXC family of chemokines (CXCL1 to 17) are small (8 to 10 kDa) secreted proteins that attract neutrophils and lymphocytes. These chemokines signal through chemokine receptors (CXCR) 1 to 8. Several studies have reported that these chemokines and receptors have a role in either the promotion or inhibition of cancer, depending on their capacity to suppress or stimulate the action of the immune system, respectively. In general terms, activation of the CXCR1/CXCR2 pathway or the CXCR4/CXCR7 pathway is associated with tumor aggressiveness and poor prognosis; therefore, the specific inhibition of these receptors is a possible therapeutic strategy. On the other hand, the lesser known CXCR3 and CXCR5 axes are generally considered to be tumor suppressor signaling pathways, and their stimulation has been suggested as a way to fight cancer. These pathways have been studied in tumor tissues (using immunohistochemistry or measuring mRNA levels) or serum [using enzyme-linked immuno sorbent assay (ELISA) or multiplexing techniques], among other sample types. Common variants in genes encoding for the CXC chemokines have also been investigated as possible biomarkers of the disease. This review summarizes the most recent findings on the role of CXC chemokines and their receptors in CRC and discusses their possible value as prognostic or predictive biomarkers as well as the possibility of targeting them as a therapeutic strategy.
