CircRNAs: a new target for the diagnosis and treatment of digestive system neoplasms

A circRNA is a type of endogenous noncoding RNA that consists of a closed circular RNA molecule formed by reverse splicing; these RNAs are widely distributed in a variety of biological cells. In contrast to linear RNAs, circRNAs have no 5′ cap or 3′ poly(A) tail. They have a stable structure, a high degree of conservation, and high stability, and they are richly and specifically expressed in certain tissues and developmental stages. CircRNAs play a very important role in the occurrence and progression of malignant tumors. According to their origins, circRNAs can be divided into four types: exon-derived circRNAs (ecRNAs), intron-derived circRNAs (ciRNAs), circRNAs containing both exons and introns (EIciRNAs) and intergenic circRNAs. A large number of studies have shown that circRNAs have a variety of biological functions, participate in the regulation of gene expression and play an important role in the occurrence and progression of tumors. In this paper, the structure and function of circRNAs are reviewed, along with their biological role in malignant tumors of the digestive tract, in order to provide a reference for the diagnosis and treatment of digestive system neoplasms.

Phase I trial of personalized mRNA vaccine encoding neoantigen in patients with advanced digestive system neoplasms.

e15269 Background: Cancer cells have characteristics of genetic instabilities and accumulate somatic mutations rapidly which could produce tumor specific antigens (TSAs) called as neoantigens. As the cancer vaccine based on TSAs has potential to treat the disease, personalized neoantigen-based immunotherapies are emerging. We report for the first time that vaccines are used to treat advanced digestive system neoplasms. Methods: In this single-arm, open-label, first-in-human phase I pilot study (NCT03468244) to investigate the feasibility, safety, immunogenicity and clinical activity of personalized mRNA vaccine. Patients with advanced digestive system neoplasms received up to 20 stimulatory synthetic long peptides vaccine at a dose of 0.2 mg on days 1 and 0.8mg on days 2, administered subcutaneously of every 3 weeks(Q3W) for 12 weeks. Patients was treated with standard treatments according to NCCN guideline simultaneously. Adverse Event (AE) grade categorization is according to CTCAE 4.0, and tumor response was assessed per RECIST 1.1. Immune factors and ELISPOT assay were examined every 3 weeks after vaccination. Results: As of February 1st, 2020, three patients (52yrs, 47yrs and 52yrs; ECOG PS: 0) with advanced rectal, colon and gastric cancer completed the vaccine therapy for 3-4 cycles. There were no serious adverse events, treatment-related death or severe neurotoxicity occurred in the study. The most common treatment-emergent adverse event (TEAE) was erythema at injection sites in three patients. Vaccine combined standard treatments treatment was associated with G3/4 hematological side effects: leucopenia (18%); neutropenia (9%); anemia (0); thrombocytopenia (18%). Blood samples for immune monitoring (ELISPOT and intracellular cytokine staining [ICS]) were collected pre-dose and at weeks 3 and 12. The level of IL-1β, IL-2 receptor, IL-6, IL-8, IL-10, and TNF-α increased for all patients. Especially, IL-8 and IL-2R increased significantly for more than 800 times in the patient with rectal cancer and more than 4 times in the patient with gastric cancer after injection, respectively. The PFS were 3.2, 3.0 and 3.0 months and the OS were 9.1, 6.0 and 7.8 months, respectively. Best response was 2 SD and 1 PD. Conclusions: This clinical study indicated that personalized mRNA vaccine may be safe and could activate immune response in vivo which is convinced by ELISPOT assay in vitro. Further studies are indicated to explore the personalized mRNA vaccine in gastrointestinal cancer. Clinical trial information: NCT03468244 .

Early Detection of Oncological Diseases of the Digestive System (Guidelines of the Russian Gastroenterological Association and the Russian Association of Oncologists for Primary Care Physicians)

Aim. The present guidelines intended for primary care physicians are aimed at facilitating early diagnosis of malignant tumours of the digestive system, which can significantly improve the immediate and long-term results of their treatment.General provisions. The guidelines comprise sections devoted to esophageal adenocarcinoma, esophageal squamous cell carcinoma, gastric cancer, colorectal cancer, hepatocellular carcinoma and extrahepatic bile duct and gall bladder cancer, as well as pancreatic cancer. Each section contains information on risk factors and precancerous diseases, which allows a physician to identify whether a particular patient falls into the risk group of digestive system neoplasms. It is shown how digestive system cancers can be suspected on the basis of patients’ complaints and past medical history, as well as data obtained both from a direct examination and laboratory instrumental studies. Each section offers practical algorithms in cases of suspected esophageal adenocarcinoma, esophageal squamous cell carcinoma, gastric cancer, colorectal cancer, hepatocellular carcinoma and extrahepatic bile duct and gallbladder cancer, as well as pancreatic cancer.Conclusion. The knowledge of clinical manifestations and risk factors in the development of digestive system neoplasms allows a physician to suspect cancer and devise a timely and adequate diagnostic strategy, including laboratory and instrumental studies at specialised clinical centres.