Hyperprogression under treatment with immune-checkpoint inhibitors in patients with gastrointestinal cancer: A natural process of advanced tumor progression?

Immunotherapy has shown great promise in treating various types of malignant tumors. However, some patients with gastrointestinal cancer have been known to experience rapid disease progression after treatment, a situation referred to as hyperprogressive disease (HPD). This minireview focuses on the definitions and potential mechanisms of HPD, natural disease progression in gastrointestinal malignancies, and tumor immunological microenvironment.

Osteoblast Derived Exosomes Alleviate Radiation- Induced Hematopoietic Injury.

As hematopoietic stem cells can differentiate into all hematopoietic lineages, mitigating the damage to hematopoietic stem cells is important for recovery from overdose radiation injury. Cells in bone marrow microenvironment are essential for hematopoietic stem cells maintenance and protection, and many of the paracrine mediators have been discovered in shaping hematopoietic function. Several recent reports support exosomes as effective regulators of hematopoietic stem cells, but the role of osteoblast derived exosomes in hematopoietic stem cells protection is less understood. Here, we investigated that osteoblast derived exosomes could alleviate radiation damage to hematopoietic stem cells. We show that intravenous injection of osteoblast derived exosomes promoted WBC, lymphocyte, monocyte and hematopoietic stem cells recovery after irradiation significantly. By sequencing osteoblast derived exosomes derived miRNAs and verified in vitro, we identified miR-21 is involved in hematopoietic stem cells protection via targeting PDCD4. Collectively, our data demonstrate that osteoblast derived exosomes derived miR-21 is a resultful regulator to radio-protection of hematopoietic stem cells and provide a new strategy for reducing radiation induced hematopoietic injury.

Research on Mechanism of miR-214 Packaged with Lipidosome Nanoparticles on Prompting the Apoptosis of Intestinal Cancer Through Regulating p53 Pathway.

Our study aimed at studying mechanism of miR-214 packaged with lipidosome nanoparticles on prompting apoptosis of intestinal cancer through regulating p53 pathway. SW480 cells were divided into blank group, empty carrier group, agonist group and group with carrier and antagonist. The negative control group was set, and groups related to p53 pathway were set as agonist group, inhibitor group and group with antagonist and inhibitor. The effect of miR-214 packaged with lipidosome nanoparticles on proliferation and apoptosis of intestinal cancer cells and p53 pathway in intestinal cancer cells was observed. Expression level of miR-214 in group with carrier and antagonist was lower than in other groups. The proportion of active cells in the group with carrier and antagonist started to be reduced notably from the second day. There was no notable declining tendency active cells' proportion from other groups. The quantity of cell apoptosis in group with carrier and antagonist was higher than in the other groups. The expression level of cleaved Caspase-3 in the group with carrier and antagonist was notably higher than in the other groups. Moreover, expression of Bcl-2/Bax protein was reversed, while expression of p53 protein in the carrier and antagonist groups was notably higher than in the other groups. The antagonist of miR-214 packaged with lipidosome nanoparticles could target on p53 pathway. The activity of p53 pathway was reduced by miR-214, and expression of Bcl-2 was increased. The expressions levels of Bax and cleaved Caspase-3 were also reversed, and molecular mechanism was mainly related with restraining of p53 signal pathway.