Autophagy: A Potential Therapeutic Target to Tackle Drug Resistance in Multiple Myeloma.

Multiple myeloma (MM) is the second most prevalent hematologic malignancy. In the past few years, the survival of MM patients has increased due to the emergence of novel drugs and combination therapies. Nevertheless, one of the significant obstacles in treating most MM patients is drug resistance, especially for individuals who have experienced relapses or developed resistance to such cutting-edge treatments. One of the critical processes in developing drug resistance in MM is autophagic activity, an intracellular self-digestive process. Several possible strategies of autophagy involvement in the induction of MM-drug resistance have been demonstrated thus far. In multiple myeloma, it has been shown that High mobility group box protein 1 (HMGB1)-dependent autophagy can contribute to drug resistance. Moreover, activation of autophagy via proteasome suppression induces drug resistance. Additionally, the effectiveness of clarithromycin as a supplemental drug in treating MM has been reported recently, in which autophagy blockage is proposed as one of the potential action mechanisms of CAM. Thus, a promising therapeutic approach that targets autophagy to trigger the death of MM cells and improve drug susceptibility could be considered. In this review, autophagy has been addressed as a survival strategy crucial for drug resistance in MM.

Genotyping Helicobacter pylori and fgf7 gene expression in gastric cancer.

BACKGROUND: Helicobacter pylori as the causative agent of the most common chronic bacterial infectious disease in human still involves a range of clinical challenging complications. In this meantime, the survey of the interaction between H. pylori virulence genes expression and its consequences on gastric antral epithelial cells is Controversial. This study surveyed the correlations between H. pylori cag Pathogenicity Island and virulence factors genes with Fgf7 gene expression as an angiogenic factor in developing gastric cancer in gastric antral epithelial cells of patients with H. pylori infection. METHOD: Gastric antral biopsy samples collected from patients out of exclusion criteria, including consumption of tobacco, alchohol and anti-H. pylori drugs, were categorized into gastric cancer (case group n:53) and gastritis (control group n:50) with and without H. pylori infection to detect changes in cDNA of fgf7 in gastric antral epithelial cells by using Real Time RT PCR. Extracted total RNA from gastric antral biopsy samples was used to synthesize cDNA for real time PCR. Furthermore, the cDNA of H. pylori cag Pathogenicity Island and other virulence factors genes were detected by using specific designed primers and simple PCR. RESULTS: Fgf7 gene expression revealed a significantly increase in gastric antral epithelial cells of gastric cancer and H. pylori-positive patients in contrast with gastritis and H. pylori-negative patients (p < 0.05). In the meanwhile, cag Pathogenicity Island and hopQ genotypes showed a positive correlation with Fgf7 gene expression (fold changes of cDNA) in gastric antral epithelial cells (p < 0.05). CONCLUSION: This study revealed an obvious correlation between Fgf7 gene expression in gastric antral epithelial cells of patients with H. pylori carcinogenic genotypes infection and some host factors including age.

Cell Survival Effects of Autophagy Regulation on Umbilical Cord-Derived Mesenchymal Stem Cells Following Exposure to Oxidative Stress.

BACKGROUND: Due to oxidative stress, hypoxia, and serum deprivation, a large percentage of mesenchymal stem cells (MSCs) die in the early stages of transplantation. The present study aimed to address whether induction or inhibition of autophagy would affect the viability of MSCs after exposure to oxidative stress. METHODS: MSCs were isolated from umbilical cord tissue using the Ficoll gradient method. pCMV-GFP-LC-3 plasmid containing GFP-tagged LC3 was transfected into MSCs to assay autophagy level in these valuable cells. The four study groups were: MSC-LC3-Rapa, MSC-LC3-3MA, MSCs without any transfection, and MSC-GFP-LC3 (control groups). To induce autophagy, the MSC-GFP-LC3 was treated with different concentrations of Rapa for 24 hours and named MSC-LC3-Rapa. To inhibit autophagy in MSC-GFP-LC3, these cells were cultured in the presence of 3MA for 24 hours and named MSC-LC3-3MA. Non-treated MSC-GFP-LC3 and MSCs were considered as control groups. MSCs were exposed to lethal doses of H2O2 followed by cell viability evaluation with the water-soluble tetrazolium salt assay method. The data were analyzed with SPSS version 18.0 using one-way ANOVA test. P<0.05 was considered statistically significant. RESULTS: The results revealed that the enhancement of autophagy in MSC-LC3-Rapa sensitized them against oxidative stress (P=0.0006) and inhibition of autophagy in MSC-LC3-3MA led to resistance against oxidative stress (P=0.0003). CONCLUSION: Inhibition of autophagy, as a non-genetic engineering method, in MSCs enhances cell viability following exposure to the oxidative stress. This may provide a novel strategy to promote the efficiency of MSC-based cell therapy for clinical applications.

Case report: Understanding the impact of persistent tissue-localization of SARS-CoV-2 on immune response activity via spatial transcriptomic analysis of two cancer patients with COVID-19 co-morbidity.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected half a billion people, including vulnerable populations such as cancer patients. While increasing evidence supports the persistence of SARS-CoV-2 months after a negative nasopharyngeal swab test, the effects on long-term immune memory and cancer treatment are unclear. In this report, we examined post-COVID-19 tissue-localized immune responses in a hepatocellular carcinoma (HCC) patient and a colorectal cancer (CRC) patient. Using spatial whole-transcriptomic analysis, we demonstrated spatial profiles consistent with a lymphocyte-associated SARS-CoV-2 response (based on two public COVID-19 gene sets) in the tumors and adjacent normal tissues, despite intra-tumor heterogeneity. The use of RNAscope and multiplex immunohistochemistry revealed that the spatial localization of B cells was significantly associated with lymphocyte-associated SARS-CoV-2 responses within the spatial transcriptomic (ST) niches showing the highest levels of virus. Furthermore, single-cell RNA sequencing data obtained from previous (CRC) or new (HCC) ex vivo stimulation experiments showed that patient-specific SARS-CoV-2 memory B cells were the main contributors to this positive association. Finally, we evaluated the spatial associations between SARS-CoV-2-induced immunological effects and immunotherapy-related anti-tumor immune responses. Immuno-predictive scores (IMPRES) revealed consistent positive spatial correlations between T cells/cytotoxic lymphocytes and the predicted immune checkpoint blockade (ICB) response, particularly in the HCC tissues. However, the positive spatial correlation between B cells and IMPRES score was restricted to the high-virus ST niche. In addition, tumor immune dysfunction and exclusion (TIDE) analysis revealed marked T cell dysfunction and inflammation, alongside low T cell exclusion and M2 tumor-associated macrophage infiltration. Our results provide in situ evidence of SARS-CoV-2-generated persistent immunological memory, which could not only provide tissue protection against reinfection but may also modulate the tumor microenvironment, favoring ICB responsiveness. As the number of cancer patients with COVID-19 comorbidity continues to rise, improved understanding of the long-term immune response induced by SARS-CoV-2 and its impact on cancer treatment is much needed.

Effects of Gliadin on Autoimmune Responses of Central Nervous System of C57BL/6 Mice.

Gluten sensitivity contributes to various degrees of neurological manifestations and neurodegenerative immunological changes. We investigated the experimental features of anti-gliadin immune responses in the central nervous system (CNS) of mice. Female C57BL6 mice were divided into three groups. Mice immunized with complete Freund's adjuvant (CFA) or gliadin emulsified in CFA, and the control group received phosphate-buffered saline (PBS). Immunohistochemistry, hematoxylin-eosin, and Luxol fast blue staining were performed on the sections. The serum levels of interleukin (IL)-17 and interferon-gamma (IFN-γ) were measured using enzyme-linked immunosorbent assay (ELISA). Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the mRNA levels of chemokine (C-X-C motif) ligand-2 (CXCL-2), C-C motif chemokine ligand-2 (CCL-2), and CXCL-10.  In gliadin+CFA immunized mice, the microscopic lesions included perivascular edema, focal-microgliosis, and acute neuronal necrosis in the cortex, subcortical, Purkinje cell layer, and ventral horn of the spinal cord. While extravasation of anti-IgG antibodies and selective targeting of Purkinje cells were observed in gliadin+CFA immunized mice. A significant increase in serum IL-17 and IFN-g levels (p<0.05), as well as expression of CXCL-2, CCL-2, and CXCL-10 in mice immunized with gliadin+CFA, were monitored versus controls. Our findings indicated that the immune responses directed against gliadin peptides might contribute to blood-brain barrier breakdown, extravasation of serum anti-IgG, gliosis, and acute neuronal necrosis in the cortex and cerebellar Purkinje cells. Anti-IgG antibodies may cause extravasation of blood-born anti-gliadin antibodies and selective targeting of Purkinje cells observed in mice immunized with peptide tryptic (pt) -gliadin in CFA.

Hydrogen Peroxide Preconditioning Promotes Protective Effects of Umbilical Cord Vein Mesenchymal Stem Cells in Experimental Pulmonary Fibrosis.

Purpose: Idiopathic pulmonary fibrosis (IPF) is a progressive lung disorder with few available treatments. Mesenchymal stem cell therapy (MSCT), an innovative approach, has high therapeutic potential when used to treat IPF. According to recent data, preconditioning of MSCs can improve their therapeutic effects. Our research focuses on investigating the anti-inflammatory and antifibrotic effects of H2 O2 -preconditioned MSCs (p-MSCs) on mice with bleomycin-induced pulmonary fibrosis (PF). Methods: Eight-week-old male C57BL/6 mice were induced with PF by intratracheal (IT) instillation of bleomycin (4 U/kg). Human umbilical cord vein-derived MSCs (hUCV-MSCs) were isolated and exposed to a sub-lethal concentration (15 µM for 24 h) of H2 O2 in vitro. One week following the injection of bleomycin, 2×105 MSCs or p-MSCs were injected (IT) into the experimental PF. The survival rate and weight of mice were recorded, and 14 days after MSCs injection, all mice were sacrificed. Lung tissue was removed from these mice to examine the myeloperoxidase (MPO) activity, histopathological changes (hematoxylin-eosin and Masson's trichrome) and expression of transforming growth factor beta 1 (TGF-ß1) and alpha-smooth muscle actin (α-SMA) through immunohistochemistry (IHC) staining. Results: Compared to the PF+MSC group, p-MSCs transplantation results in significantly decreased connective tissue (P<0.05) and collagen deposition. Additionally, it is determined that lung tissue in the PF+pMSC group has increased alveolar space (P<0.05) and diminished expression of TGF-ß1 and α-SMA. Conclusion: The results demonstrate that MSCT using p-MSCs decreases inflammatory and fibrotic factors in bleomycin-induced PF, while also able to increase the therapeutic potency of MSCT in IPF.

CD93 is Selectively Expressed on Human Myeloma Cells but Not on B Lymphocytes.

BACKGROUND: CD93 has originally been known as a C1q receptor, and many studies have demonstrated that CD93 is expressed on hematopoietic stem cells, B cell progenitors, myeloid and monocytic cells. Moreover, CD93 is shown to be expressed on long-lived plasma cells, and CD93 deficient-mice display an impairment in plasma cell development. OBJECTIVE: To investigate the expression of CD93 on multiple myeloma (MM) cells. METHODS: Human MM and B cell lines were cultured, and the expression of CD93 was examined on these cells by quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) and Fluorescence Activated Cell Sorting (FACS). In addition, CD19+ primary B cells and CD19-/CD138+ primary MM cells were isolated by MACS columns, and CD93 expression was further analyzed on these cells. RESULTS: qRT-PCR data showed that CD93 expression at mRNA level was much higher in MM cell lines compared with B cell lines. In addition, MM cell lines expressed a higher amount of surface CD93 at protein level compared with B cell lines. More importantly, CD93 expression was significantly higher in CD19-/CD138+ primary MM cells than in CD19+ primary B cells isolated from the bone marrow of patients with MM. CONCLUSION: We demonstrated that CD93 is expressed on myeloma cells and, that CD93 could play a key role in the pathogenesis of MM. Further studies are necessary to explore this possible role.

Dual Preconditioning: A Novel Strategy to Withstand Mesenchymal Stem Cells against Harsh Microenvironments.

Purpose: Poor survival rate of mesenchymal stem cells (MSCs) following their transplantation is one of the major challenges in their therapeutic application. Therefore, it is necessary to augment the viability of the MSCs in order to improve their therapeutic efficacy. Several strategies have been used to overcome this problem. Preconditioning of MSCs with oxidative stresses has gained a lot of attention. Therefore, in the present study, we investigated the effects of simultaneous preconditioning of MSCs with hydrogen peroxide and serum deprivation stresses on their survival and resistance to stressful conditions. Methods: MSCs were isolated from human umbilical cord blood. To perform simultaneous preconditioning, the cells were cultured in DMEM medium containing 1, 2.5 and 5 percent FBS and different concentrations of H2O2 (5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 80 and 100 µM) for 24 hrs. Then, the cells were cultured in recovery culture medium. Finally, one group of the cells was exposed to a lethal concentration of H2O2 (300µM), and the other cells were cultivated in FBS free DMEM medium as the lethal situation. In addition, the percentage of apoptotic cells was analyzed using Caspase 3 assay kit. Results: Simultaneous preconditioning of the MSCs with 15µM H2O2 plus serum deprivation, 2.5% FBS, significantly increased the resistance of the cells to the toxicity induced following their cultivation in FBS free DMEM medium. It exerted the protective effect on the cells after treating with the lethal dose of H2O2 as well. Conclusion: Simultaneous preconditioning of MSCs with oxidative and serum deprivation stresses enhances their survival against harsh conditions, which might increase the viability and stability of the MSCs following their transplantation.