LGR5 rs17109924 is a predictive genetic biomarker for time to recurrence in patients with colon cancer treated with 5-fluorouracil-based adjuvant chemotherapy

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

The Clinical and Theranostic Values of Activated Leukocyte Cell Adhesion Molecule (ALCAM)/CD166 in Human Solid Cancers

Simple Summary

ALCAM (activated leukocyte cell adhesion molecule) is an important regulator in human cancers, particularly solid tumours. Its expression in cancer tissues has prognostic values depending on cancer types and is also linked to distant metastases. A truncated form, soluble form of ALCAM (sALCAM) in circulation has been suggested to be a prognostic indicator and a potential therapeutic tool. This article summarises recent findings and progress in ALCAM and its involvement in cancer, with a primary focus on its clinical connections and therapeutic values.

Abstract

Activated leukocyte cell adhesion molecule (ALCAM), also known as CD166, is a cell adhesion protein that is found in multiple cell types. ALCAM has multiple and diverse roles in various physiological and pathological conditions, including inflammation and cancer. There has been compelling evidence of ALCAM’s prognostic value in solid cancers, indicating that it is a potential therapeutic target. The present article overviews the recent findings and progress in ALCAM and its involvement in cancer, with a primary focus on its clinical connections in cancer and therapeutic values.

Dickkopf-2 regulates the stem cell marker LGR5 in colorectal cancer via HNF4α1

Enhanced stemness in colorectal cancer has been reported and it contributes to aggressive progression, but the underlying mechanisms remain unclear. Here we report a Wnt ligand, Dickkopf-2 (DKK2) is essential for developing colorectal cancer stemness. Genetic depletion of DKK2 in intestinal epithelial or stem cells reduced tumorigenesis and expression of the stem cell marker genes including LGR5 in a model of colitis-associated cancer. Sequential mutations in APC, KRAS, TP53, and SMAD4 genes in colonic organoids revealed a significant increase of DKK2 expression by APC knockout and further increased by additional KRAS and TP53 mutations. Moreover, DKK2 activates proto-oncogene tyrosine-protein kinse Src followed by increased LGR5 expressing cells in colorectal cancer through degradation of HNF4α1 protein. These findings suggest that DKK2 is required for colonic epithelial cells to enhance LGR5 expression during the progression of colorectal cancer.

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APC, KRAS, and TP53 mutations induce DKK2 expression in murine colon cancer

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DKK2 increases Src phosphorylation in colon cancer cells

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Activated Src leads to degradation of HNF4α1 protein

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This DKK2 downstream signaling enhances LGR5 expression in colon cancer

Targeting LGR5 in Colorectal Cancer: therapeutic gold or too plastic?

Leucine-rich repeat-containing G-protein coupled receptor (LGR5 or GPR49) potentiates canonical Wnt/β-catenin signalling and is a marker of normal stem cells in several tissues, including the intestine. Consistent with stem cell potential, single isolated LGR5⁺ cells from the gut generate self-organising crypt/villus structures in vitro termed organoids or 'mini-guts', which accurately model the parent tissue. The well characterised deregulation of Wnt/β-catenin signalling that occurs during the adenoma-carcinoma sequence in colorectal cancer (CRC) renders LGR5 an interesting therapeutic target. Furthermore, recent studies demonstrating that CRC tumours contain LGR5⁺ subsets and retain a degree of normal tissue architecture has heightened translational interest. Such reports fuel hope that specific subpopulations or molecules within a tumour may be therapeutically targeted to prevent relapse and induce long-term remissions. Despite these observations, many studies within this field have produced conflicting and confusing results with no clear consensus on the therapeutic value of LGR5. This review will recap the various oncogenic and tumour suppressive roles that have been described for the LGR5 molecule in CRC. It will further highlight recent studies indicating the plasticity or redundancy of LGR5⁺ cells in intestinal cancer progression and assess the overall merit of therapeutically targeting LGR5 in CRC.

Advances and perspectives of colorectal cancer stem cell vaccine

Colorectal cancer is essentially an environmental and genetic disease featured by uncontrolled cell growth and the capability to invade other parts of the body by forming metastases, which inconvertibly cause great damage to tissues and organs. It has become one of the leading causes of cancer-related mortality in the developed countries such as United States, and approximately 1.2 million new cases are yearly diagnosed worldwide, with the death rate of more than 600,000 annually and incidence rates are increasing in most developing countries. Apart from the generally accepted theory that pathogenesis of colorectal cancer consists of genetic mutation of a certain target cell and diversifications in tumor microenvironment, the colorectal cancer stem cells (CCSCs) theory makes a different explanation, stating that among millions of colon cancer cells there is a specific and scanty cellular population which possess the capability of self-renewal, differentiation and strong oncogenicity, and is tightly responsible for drug resistance and tumor metastasis. Based on these characteristics, CCSCs are becoming a novel target cells both in the clinical and the basic studies, especially the study of CCSCs vaccines due to induced efficient immune response against CCSCs. This review provides an overview of CCSCs and preparation technics and targeting factors related to CCSCs vaccines in detail.

Association of cancer stem cell markers genetic variants with gallbladder cancer susceptibility, prognosis, and survival

Genes important to stem cell progression have been involved in the genetics and clinical outcome of cancers. We investigated germ line variants in cancer stem cell (CSC) genes to predict susceptibility and efficacy of chemoradiotherapy treatment in gallbladder cancer (GBC) patients. In this study, we assessed the effect of SNPs in CSC genes (surface markers CD44, ALCAM, EpCAM, CD133) and (molecular markers NANOG, SOX-2, LIN-28A, ALDH1A1, OCT-4) with GBC susceptibility and prognosis. Total 610 GBC patients and 250 controls were genotyped by using PCR-RFLP, ARMS-PCR, and TaqMan allelic discrimination assays. Chemotoxicity graded 2-4 in 200 patients and tumor response was recorded in 140 patients undergoing neoadjuvant chemotherapy (NACT). Differences in genotype and haplotype frequency distributions were calculated by binary logistic regression. Gene-gene interaction model was analyzed by generalized multifactor dimensionality reduction (GMDR). Overall survival was assessed by Kaplan-Meier survival curve and multivariate Cox-proportional methods. ALCAM Ars1157Crs10511244 (P = 0.0035) haplotype was significantly associated with GBC susceptibility. In GMDR analysis, ALCAM rs1157G>A, EpCAM rs1126497T>C emerged as best significant interaction model with GBC susceptibility and ALDH1A1 rs13959T>G with increased risk of grade 3-4 hematological toxicity. SOX-2 rs11915160A>C, OCT-4 rs3130932T>G, and NANOG rs11055786T>C were found best gene-gene interaction model for predicting response to NACT. In both Cox-proportional and recursive partitioning ALCAM rs1157GA+AA genotype showed higher mortality and hazard ratio. ALCAM gene polymorphisms associated with GBC susceptibility and survival while OCT-4, SOX-2, and NANOG variants showed an interactive role with treatment response.

Genetic markers of recurrence in colorectal cancer

Colorectal cancer (CRC) worldwide belongs to one of the most frequent cancers affecting both genders. Surgery and 5-fluorouracil-based adjuvant chemotherapy are recommended for patients with high-risk stage II and stage III colon carcinoma. Mutations of genes encoding for specific proteins may have an impact on the time to recurrence. These proteins act over specific signaling pathways, are implicated in metabolic processes and regulate the cell cycle. Though many retrospective studies show strong associations between genetic mutations and the clinical outcome of patients with CRC, currently no validated biomarkers are used in clinical routine settings. Therefore, large prospective validation studies should be carried out in order to strengthen the position of genetic mutations in personalized treatment of patients with CRC.