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Solute carrier family (SLC) transporters are expressed in the digestive system and play important roles in maintaining physiological functions in the body. In addition, SLC transporters act as oncoproteins or tumor-suppressor proteins during the development, progression, and metastasis of various digestive system cancers. SLC22A18, a member of the SLC22 gene family, is an orphan transporter with an unknown endogenous substrate. Previous study revealed that SLC22A18 is downregulated in colorectal cancer tissues and that it acts as a suppressor in colorectal cancer, although the effects of SLC22A18 variants on colon cancer cell proliferation, migration, and invasion are unknown. Therefore, in this study, we identified SLC22A18 variants found in multiple populations by searching public databases and determined the in vitro effects of these missense variations on transporter expression and cancer progression. Our results indicated that three missense SLC22A18 variants—p.Ala6Thr, p.Arg12Gln, and p.Arg86His—had significantly lower cell expression than the wild type, possibly owing to intracellular degradation. Furthermore, these three variants caused significantly higher proliferation, migration, and invasion of colon cancer cells than the wild type. Our findings suggest that missense variants of SLC22A18 can potentially serve as biomarkers or prognostic tools that enable clinicians to predict colorectal cancer progression. [ABSTRACT FROM AUTHOR]

Background and Aim: It remains unclear whether immunotherapy, which is not generally considered for microsatellite stable (MSS) colorectal cancer (CRC), can be used to effectively treat select CRC patients. We investigated the feasibility of obesity‐associated MSS CRC patients for immunotherapy based on genomic alterations. Methods: We evaluated differences in genomic alteration types and immune signatures between obese and non‐obese patients with MSS CRC. We performed genomic analyses using 434 CRC patients from The Cancer Genome Atlas (TCGA). Patients with MSS CRC were stratified into subgroups based on their BMI and numbers of nonsynonymous single nucleotide variants (nsSNVs) and frameshift insertions and deletions (fs INDELs) using machine learning. Results: The obese subgroup showed higher incidences of single nucleotide variants (SNV) and insertions and deletions (INDELs) in comparison with healthy weight patients with MSS CRC. The subgroup, who had higher numbers of nsSNVs and fs INDLEs, exhibited increased immune signatures, increased number of SNV‐derived neoantigens, and had up‐regulated two immune checkpoint genes in comparison with healthy weight patients with MSS CRC, reflecting interactions between the cancer genome and immune system. Conclusions: This study suggests that immunotherapy may be suitable for some obesity‐associated CRC patients. [ABSTRACT FROM AUTHOR]