The PI3K/Akt/mTOR axis in colorectal cancer: Oncogenic alterations, non-coding RNAs, therapeutic opportunities, and the emerging role of nanoparticles.

Colorectal cancer (CRC) is one of the deadliest human malignancies worldwide. Several molecular pathways have been demonstrated to be involved in the initiation and development of CRC which among them, the overactivation of the phosphatidyl-inositol 3-kinase (PI3K)/Akt/mTOR axis is of importance. The current review aims to unravel the mechanisms by which the PI3K/Akt/mTOR pathway affects CRC progression; and also, to summarize the original data obtained from international research laboratories on the oncogenic alterations and polymorphisms affecting this pathway in CRC. Besides, we provide a special focus on the regulatory role of noncoding RNAs targeting the PI3K/Akt/mTOR pathway in this malignancy. Questions on how this axis is involved in the inhibition of apoptosis, in the induction of drug resistance, and the angiogenesis, epithelial to mesenchymal transition, and metastasis are also responded. We also discussed the PI3K/Akt pathway-associated prognostic and predictive biomarkers in CRC. In addition, we provide a general overview of PI3K/Akt/mTOR pathway inhibition whether by chemical-based drugs or by natural-based medications in the context of CRC, either as monotherapy or in combination with other therapeutic agents; however, those treatments might have life-threatening side effects and toxicities. To the best of our knowledge, the current review is one of the first ones highlighting the emerging roles of nanotechnology to overcome challenges related to CRC therapy in the hope that providing a promising platform for the treatment of CRC.

Unleashing the Impact of Exosomes Derived from Human Placental Mesenchymal Stem Cells (hPMSCs) on U-266 Myeloma Cell Line.

Multiple myeloma (MM) is a malignancy of plasma cells, terminally differentiated B cells, with complications like hypercalcemia, renal failure, anemia, and bone disease, which are also known as CRAB criteria. MM develops from monoclonal gammopathy of unknown significance (MGUS), a pre-malignant plasma cell dyscrasia. Over some time, MGUS has the potential to progress into smoldering multiple myeloma (SMM), which can evolve into MM. MM rarely progresses into plasma cell leukemia (PCL), a condition in which malignant plasma cells no longer stay in the bone marrow niche and circulate in the peripheral blood. In MM, various soluble factors play important roles, and interleukin-6 has different vital roles.  Interleukin-6, an inflammatory cytokine, has significant roles in the growth, survival, angiogenesis, metastasis, and apoptosis resistance in MM. Interleukin-6 is produced and secreted by both autocrine from myeloma cells and paracrine from bone marrow stromal cells. To tackle MM, various therapeutic approaches were applied over many years, and according to the results, most patients with MM can respond well to first-line treatment. However, the majority of patients may relapse as conventional treatment may not be curative. So, there is an urgent need for novel cell-based and cell-free therapeutic strategies, such as mesenchymal stem cell-based therapies and their products to offer new therapeutic strategies for MM. Materials and Methods: In the present study, we investigated the impacts of exosomes derived from human placental mesenchymal stem cells (hPMSCs) on apoptosis and interleukin-6 expression in a myeloma cell line, U-266, for the first time. hPMSCs were isolated from the human placenta and cultured in a DMEM medium. After characterizing the cells and acknowledging their identity, they underwent several passages and their supernatant was collected to harvest exosomes. The exosomes were isolated by ultracentrifugation and characterized by DLS and TEM, and their concentration was measured by BCA protein assay. U266 cells were treated with different concentrations of exosomes and then MTT and annexin/propidium iodide flow cytometry tests were performed to evaluate cell viability. Afterward, a real-time PCR test was performed to evaluate interleukin-6 gene expression. Results: According to our findings, treatment of U-266 cells with hPMSCS-derived exosomes led to the preservation of myeloma cells without changes in their cell cycle. Surprisingly, treatments did not hinder the expression of interleukin-6 in the myeloma cells. Conclusion: In MM patients, interleukin-6 pl ays different roles, and it is a desirable target to design new therapeutic strategies. To evaluate the effects of new therapeutic strategies, we designed and performed our study to estimate the effects of cell-free therapeutic strategy.  In the present study, the impacts of hPMSCS-derived exosomes on the viability of MM cells and interleukin-6 gene expression were evaluated. The results showed that hPMSCS-derived exosomes resulted in the perseverance of myeloma cells without changes in the cell cycle.  Furthermore, the interleukin-6 gene expression level showed no significant change.

CAR NK cell therapy in hematologic malignancies and solid tumors; obstacles and strategies to overcome the challenges.

Adoptive cell treatment (ACT) utilizing chimeric antigen receptors (CAR) diverts the specificity of safe cells against a target-specific antigen and portrays exceptional potential for cancer treatment. While CAR T cell treatment has risen as a breakthrough with unprecedented results within the therapeutic procedures of human malignancies, different deficiencies including challenging and costly generation processes, strict patient qualification criteria, and undesirable toxicity have ruined its application. Unlike T cells, the application of natural killer (NK) cells has attracted consideration as a reasonable alternative owing to the major histocompatibility complex (MHC)-independency, shorter life expectancy, the potential to create an off-the-shelf immune product, and potent antitumor properties. In this article, we provide an updated review of the differences between CAR T and CAR NK cells, current enhancements in CAR NK design, the available sources for collecting NK cells, and strategies for the transduction step of the CARs to NK cells. Furthermore, we focus on the published and ongoing preclinical and clinical studies of CAR NK treatment strategies both in hematologic malignancies and solid tumors. We also discuss limitations and plausible solutions to improve the perseverance, function, safety, and efficacy of CAR NK cells with a special focus on solid tumors.

The PI3K/Akt/mTOR signaling pathway in gastric cancer; from oncogenic variations to the possibilities for pharmacologic interventions.

Genetic and epigenetic alterations have been under concentrated investigations for many years in order to unearth the molecules regulating human cancer pathogenesis. However, the identification of a wide range of dysregulated genes and their protein products has raised a question regarding how the results of this large collection of alterations could converge into a formation of one malignancy. The answer may be found in the signaling cascades that regulate the survival and metabolism of the cells. Aberrancies of each participant molecule of such cascades may well result in augmented viability and unlimited proliferation of cancer cells. Among various signaling pathways, the phosphatidylinositol-3-kinase (PI3K) axis has been shown to be activated in about one-third of human cancers. One of the malignancies that is mostly affected by this axis is gastric cancer (GC), one of the most fatal cancers worldwide. In the present review, we aimed to illustrate the significance of the PI3K/Akt/mTOR axis in the pathogenesis of GC and also provided a wide perspective about the application of the inhibitors of this axis in the therapeutic strategies of this malignancy.