Treatment of Gastrointestinal Stromal Tumors (GISTs): A Focus on Younger Patients

Characterization of a Human Gastrointestinal Stromal Tumor Cell Line Established by SV40LT-Mediated Immortalization

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the digestive tract and originate from the interstitial cells of Cajal (ICC), which is the pacemaker for peristaltic movement in the gastrointestinal tract. Existing GIST cell lines are widely used as cell models for in vitro experimental studies because the mutation sites are known. However, the immortalization methods of these cell lines are unknown, and no Chinese patient-derived GIST cell lines have been documented. Here, we transfected simian virus 40 large T antigen (SV40LT) into primary GIST cells to establish an immortalized human GIST cell line (ImGIST) for the first time. The ImGIST cells had neuronal cell-like irregular radioactive growth and retained the fusion growth characteristics of GIST cells. They stably expressed signature proteins, maintained the biological and genomic characteristics of normal primary GIST cells, and responded well to imatinib, suggesting that ImGIST could be a potential in vitro model for research in GIST to explore the molecular pathogenesis, drug resistance mechanisms, and the development of new adjuvant therapeutic options.

Bioinformatic analysis of KIT juxtamembrane domain mutations in Syrian GIST patients: jigsaw puzzle completed

BACKGROUND

The huge number of detected somatic KIT mutations highlights the necessity of in silico analyses that are almost absent in the relevant medical literature. The aim of this study is to report the mutation spectrum analysis of exon 11 encoding the juxtamembrane (JM) domain of the KIT gene in a group of Syrian GIST patients.

METHODS

Forty-eight formalin-fixed paraffin-embedded GIST tissue samples, collected between 2006 and 2016, were retrieved from the pathological archives and analyzed for KIT exon 11 mutations by DNA sequencing. Structural/functional impact of detected variants was predicted using several bioinformatic tools.

RESULTS

Twenty-one different variants have been detected in intron 10, exon 11, and intron 11 of the KIT gene, eight of which were novel changes. Mutations in exon 11 of the KIT gene were detected in 28 of 48 (58.3%) GIST patients and predicted to be pathogenic and cancer promoting. Specifically, age above 60 was very significantly associated with the negative selection of deletion mutations (p = .007), a phenomenon that points to deletion severity.

CONCLUSIONS

Six bioinformatic tools have proved efficient in predicting the impact of detected KIT variations in view of published structural, experimental, and clinical findings.

Tumor Microenvironment Remodeling in Gastrointestinal Cancer: Role of miRNAs as Biomarkers of Tumor Invasion

Gastrointestinal (GI) cancers are the most frequent neoplasm, responsible for half of all cancer-related deaths. Metastasis is the leading cause of death from GI cancer; thus, studying the processes that regulate cancer cell migration is of paramount importance for the development of new therapeutic strategies. In this review, we summarize the mechanisms adopted by cancer cells to promote cell migration and the subsequent metastasis formation by highlighting the key role that tumor microenvironment components play in deregulating cellular pathways involved in these processes. We, therefore, provide an overview of the role of different microRNAs in promoting tumor metastasis and their role as potential biomarkers for the prognosis, monitoring, and diagnosis of GI cancer patients. Finally, we relate the possible use of nutraceuticals as a new strategy for targeting numerous microRNAs and different pathways involved in GI tumor invasiveness.

Young-Onset Cancers-Early Steps in the Right Direction

The global incidence of young-onset (YO) cancer is on the rise [...].

Gastric gastrointestinal stromal tumors. Is there a necessity to use imatinib in the intermediate-risk group?

BACKGROUND

A gastrointestinal stromal tumor (GIST) is a tumor that occurs in the gastrointestinal tract, most frequently in the stomach or small intestine. This study aimed to reveal the clinical, histopathological, and immunohistochemical features of patients with GIST and to determine the effect of adjuvant tyrosine kinase inhibitor (TKI) use on survival rates in intermediate-risk gastric GIST cases.

METHODS

Clinical characteristics, histopathological findings, and oncological outcomes of 51 patients operated on for gastric GIST between 2010 and 2019 were analyzed retrospectively. Patients treated with neoadjuvant and adjuvant TKI were identified. The effect of adjuvant therapy on survival in the intermediate-risk group was examined.

RESULTS

There were 33 females and 18 males, with a mean age of 64.9 ± 12.8 years. The most common surgical procedure was gastric wedge resection. Three cases were treated with laparoscopy, and 48 underwent open surgery. A multi-visceral resection was carried out in three cases. All cases underwent R0 resection. In the intermediate-risk group, there were no statistical differences between individuals receiving adjuvant therapy (n =12) and those not receiving adjuvant therapy (n =6) regarding survival rates (p =0.157). The average follow-up period was 54.9 (min: 2 - max: 106) months. Over this period, in three and five patients, recurrence and metastases occurred, respectively, and seven patients succumbed to the disease. Disease-free survival for five years was 93.7 %, metastasis-free survival was 83.4 %, and overall survival was 86.7 %. HIPPOKRATIA 2021, 25 (3):113-118.

CONCLUSIONS

This study showed that adjuvant TKI therapy did not affect survival rates in intermediate-risk gastric GIST.