Search

Gastric cancer (GC) remains one of the most common and malignant types of cancer due to its rapid progression, distant metastasis, and resistance to conventional chemotherapy, although efforts have been made to understand the underlying mechanism of this resistance and to improve clinical outcome. It is well recognized that tumor heterogeneity, a fundamental feature of malignancy, plays an essential role in the cancer development and chemoresistance. The model of tumor-initiating cell (TIC) has been proposed to explain the genetic, histological, and phenotypical heterogeneity of GC. TIC accounts for a minor subpopulation of tumor cells with key characteristics including high tumorigenicity, maintenance of self-renewal potential, giving rise to both tumorigenic and non-tumorigenic cancer cells, and resistance to chemotherapy. Regarding tumor-initiating cell of GC (GATIC), substantial studies have been performed to (1) identify the putative specific cell markers for purification and functional validation of GATICs; (2) trace the origin of GATICs; and (3) decode the regulatory mechanism of GATICs. Furthermore, recent studies demonstrate the plasticity of GATIC and the interaction between GATIC and its surrounding factors (TIC niche or tumor microenvironment). All these investigations pave the way for the development of GATIC-targeted therapy, which is in the phase of preclinical studies and clinical trials. Here, we interpret the heterogeneity of GC from the perspectives of TIC by reviewing the above-mentioned fundamental and clinical studies of GATICs. Problems encountered during the GATIC investigations and the potential solutions are also discussed., Competing Interests: Conflict-of-interest statement: No potential conflicts of interest.

Paratyphoid fever can be complicated by massive lower gastrointestinal bleeding with ileocolonic ulcerations, which are commonly localized using colonoscopy. The most common manifestations include multiple, variable-sized, round or oval-shaped, punched-out ulcers. Occasionally, massive lower gastrointestinal bleeding can occur from erosion of blood vessels. We present a rare case of severe lower gastrointestinal bleeding due to paratyphoid A fever that was successfully controlled with hemoclippings. A 30-year-old man experienced high fever and hematochezia whose blood culture showed Salmonella paratyphi A. A complete colonoscopy was successfully performed up to the level of the terminal ileum, which showed multiple, shallow, ulcerated lesions over the entire terminal ileum. A bleeding vessel was seen in one of the ulcers, with overlaying blood clots. Endoscopic hemostasis was successfully performed with four pieces of endoclip and without immediate complication. This report highlights the use of colonoscopy and endoscopic therapy with endoclips for lower gastrointestinal bleeding, which should be considered before surgery.