The Role of Serine Protease 8 in Mediating Gefitinib Resistance in Non-small Cell Lung Cancer.

OBJECTIVE: This investigation aims to explore the expression levels of serine protease 8 (PRSS8) in gefitinib-resistant Non-Small Cell Lung Cancer (NSCLC) cell lines (PC9/GR) and elucidate its mechanism of action. METHODOLOGY: We measured PRSS8 expression in gefitinib-resistant (PC9/GR) and sensitive (PC9) NSCLC cell lines using Western blot analysis. PRSS8-specific small interfering RNA (PRSS8-siRNA), a recombinant plasmid, and a corresponding blank control were transfected into PC9/GR cells. Subsequently, Western blot analyses were conducted to assess the expression levels of PRSS8, phosphorylated AKT (p-AKT), AKT, phosphorylated mTOR (p-mTOR), mTOR, and various apoptosis-related proteins within each group. Additionally, a cell proliferation assay utilizing Cell Counting Kit-8 (CCK8) was performed on each group treated with gefitinib. RESULT: PRSS8 expression was markedly higher in PC9/GR cells compared to PC9 cells (p < 0.05). The group treated with PRSS8-siRNA exhibited significantly reduced protein expression levels of PRSS8, p-AKT, p-mTOR, ß-catenin, and BCL-2 compared to the control siRNA (Con-siRNA) group, whereas expressions of Caspase9 and Bax were significantly increased. In the untransfected PC9/GR cells, protein expressions of PRSS8, p-AKT, pmTOR, and BCL-2 were significantly elevated when compared with the plasmid-transfected group, which also showed a significant reduction in Bax expression. The proliferative activity of the PRSS8-siRNA group postgefitinib treatment was significantly diminished at 24, 48, and 72 hours in comparison to the Con-siRNA group. CONCLUSION: The findings indicate that PRSS8 contributes to the acquisition of resistance to gefitinib in NSCLC, potentially through regulation of the AKT/mTOR signaling pathway.

Relationship between methylenetetrahydrofolate reductase C677T gene polymorphism and neutrophil gelatinase-associated lipocalin in early renal injury in H-type hypertension.

OBJECTIVE: To analyse the relationship between the polymorphisms of the H-type hypertensive methylenetetrahydrofolate reductase (MTHFR) C677T gene and neutrophil gelatinase-associated lipocalin (NGAL) in early kidney injury. METHOD: A total of 279 hospitalised patients with hypertension were selected and grouped according to their homocysteine (Hcy) level. If their blood Hcy level was ≥ 10 µmol/L they were assigned to the H-type hypertensive group, and if it was < 10 µmol/L they were assigned to the non-H-type hypertensive group. Blood lipid indexes, renal function indexes and blood glucose indexes were collected, and the differences between the two groups were compared. Furthermore, MTHFR C677T genotype distribution and allele frequency and Hcy level of MTHFR C677T genotype were compared, and logistic multiple regression analysis was conducted for the correlation of different genotypes of MTHFR C677T and the early kidney injury marker NGAL. RESULTS: In the non-H-type hypertensive group, the levels of Hcy and NGAL, cystatin, blood urea nitrogen, serum creatinine, uric acid, serum ß2-microglobulin and urinary microalbumin-to-creatinine ratio increased significantly, and the glomerular filtration rate level decreased significantly, when compared with the H-type hypertensive group, with statistical differences (p < 0.05). The H-type hypertensive group and the non-H-type hypertensive group had significant differences in the CC, CT and TT genotypes and allele frequencies at the MTHFR C677T locus. The MTHFR C677T gene mutation rate of the H-type hypertensive group was significantly higher than that of the non-H-type hypertensive group. The H-type hypertensive group had higher levels of the TT genotype and CT genotype Hcy. There was a statistical difference (p < 0.05). CONCLUSION: Methylenetetrahydrofolate reductase C677T polymorphism is correlated with the Hcy level, and its gene polymorphism will affect the Hcy level. Methylenetetrahydrofolate reductase C677T polymorphism has an interactive effect with NGAL. Screening NGAL and reducing Hcy levels are valuable methods for the prevention and treatment of early renal injury in patients with H-type hypertension and help improve the prognosis of patients and their quality of life.

Mechanism of GLP-1 Receptor Agonists-Mediated Attenuation of Palmitic Acid-Induced Lipotoxicity in L6 Myoblasts.

Methods: Cells were divided into 5 groups-control, high-fat, 10 nmol/L LR + 0.6 mmol/L palmitic acid (PA) (10LR), 100 nmol/L LR + 0.6 mmol/L PA (100LR), and 1000 nmol/L LR + 0.6 mmol/L PA (1000LR). CCK-8 method to detect cell viability, GPO-PAP enzymatic method to detect intracellular triglyceride content, and reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting methods to detect fatty acid translocase CD36 (FAT/CD36) and fatty acid binding protein 4 (FABP4) in L6 cells, glucose-regulated protein 78 (GRP78), glucose transporter 4 (GLUT4) expression at the mRNA and protein levels, respectively, were performed. Results: We found that after PA intervention for 24 h, the cell viability decreased significantly; the cell viability of the LR group was higher than that of the high-fat group (P < 0.01). After PA intervention, compared with those in the high-fat group, GRP-78, FAT/CD36, FABP4 mRNA ((4.36 ± 0.32 vs. 8.15 ± 0.35); (1.00 ± 0.04 vs. 2.46 ± 0.08); (2.88 ± 0.55 vs. 8.29 ± 0.52), P < 0.01) and protein ((3338.13 ± 333.15 vs. 4963.98 ± 277.29); (1978.85 ± 124.24 vs. 2676.07 ± 100.64); (3372.00 ± 219.84 vs. 6083.20 ± 284.70), both P < 0.01) expression decreased in the LR group. The expression levels of GLUT4 mRNA ((0.75 ± 0.04 vs. 0.34 ± 0.03), P < 0.01) and protein ((3443.71 ± 191.89 vs. 2137.79 ± 118.75), P < 0.01) increased. Conclusion: Therefore, we conclude that LR can reverse PA-induced cell inactivation and lipid deposition, which may be related to the change in GRP-78, FAT/CD36, FABP4, GLUT4, and other factors.

Cytokine production suppression by culture supernatant of B16F10 cells and amelioration by Ganoderma lucidum polysaccharides in activated lymphocytes.

Some cytokines, such as interleukin-2 (IL-2), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), produced by lymphocytes might play an important role in anti-tumor immunity and their production is possibly suppressed by cancer. Amelioration of the suppression of cytokine production might contribute to cancer control. Ganoderma lucidum polysaccharides (Gl-PS), a versatile group of a component of G. lucidum and one with various bioactivities, might have this potential. In this study, analyses including reverse transcription and the polymerase chain reaction (RT-PCR), immunocytochemistry and Western blot were used to test the effects of Gl-PS on the production of IL-2, IFN-γ and TNF-α in mononuclear lymphocytes by incubating Gl-PS with mouse splenic mononuclear lymphocytes in the presence of B16F10 cell culture supernatant following activation by phytohemagglutinin. The RT-PCR, immunocytochemistry and Western blot assays showed that the production of IL-2, IFN-γ and TNF-α in mononuclear lymphocytes was suppressed by B16F10 cell culture supernatant at both the mRNA and protein levels, whereas the suppression was fully or partially ameliorated by Gl-PS. The amelioration by Gl-PS against the suppression of the production of IL-2, IFN-γ and TNF-α in mononuclear lymphocytes by B16F10 cell culture supernatant might contribute to cancer control.

Suppression of the production of transforming growth factor ß1, interleukin-10, and vascular endothelial growth factor in the B16F10 cells by Ganoderma lucidum polysaccharides.

Transforming growth factor ß (TGF-ß), interleukin-10 (IL-10), and vascular endothelial growth factor (VEGF) are three of the commonly studied cytokines playing an important role in tumor initiation and progression. Besides their promotional effects on tumor progression, the three cytokines have immunosuppressive effects that facilitate tumor initiation and progression as well. Ganoderma lucidum polysaccharides (Gl-PS) with multiple bioactivities may have the effect on B16F10 melanoma cells to induce stronger antitumor immune response that has been demonstrated. Gl-PS may have the suppressive effects on the production of these three cytokines, which has yet to be demonstrated. In this study, we tested these effects of Gl-PS by incubating Gl-PS with malignant tumor cells such as B16F10 cells, a melanoma cell line, and LA795 cells, a lung carcinoma cell line. RT-qPCR and enzyme-linked immunosorbent assay showed that the production of TGF-ß1, IL-10, and VEGF in B16F10 melanoma cells and LA795 lung carcinoma cells was suppressed by Gl-PS at both mRNA and protein levels, suggesting that the suppression on production of TGF-ß, IL-10, and VEGF in B16F10 melanoma cells and LA795 lung carcinoma cells by Gl-PS may contribute to the therapy on melanoma and lung carcinoma along with the induction of stronger antitumor immune response.

Antagonism by Ganoderma lucidum polysaccharides against the suppression by culture supernatants of B16F10 melanoma cells on macrophage.

It is well-documented that macrophages have the functions to regulate antitumor immune response. Antitumor response can be launched by a series of events, starting with inflammation mediated by monocyte/macrophages, which stimulates natural killer and dendritic cells and finally activates the cytotoxic lymphoid system. Monocytes/macrophages may be the first line of defense in tumors. However, specific and nonspecific immunotherapy for human cancer has shown no success or limited success in clinical trials. Part of the reasons attribute to tumor-derived soluble factors that suppress functions of immune cells or induce apoptosis of these cells, including macrophages. Therefore, antagonism of the suppression on the macrophages is an important goal for tumor immunotherapy. To achieve this purpose, Ganoderma lucidum polysaccharides (Gl-PS) with multiple bioactivities were used on mouse peritoneal macrophages incubating with culture supernatants of B16F10 melanoma cells (B16F10-CS). It was shown that the viability, phagocytic activity, NO production, TNF-α production and activity in peritoneal macrophages after activation by lipopolysaccharide were suppressed by B16F10-CS, while the suppressions were fully or partially antagonized by Gl-PS. In conclusion, B16F10-CS is suppressive to the viability, phagocytic activity, NO production, TNF-α production and activity in peritoneal macrophages while Gl-PS had the antagonistic effects against this suppression, suggesting this potential of Gl-PS to facilitate cancer immunotherapy.

Effects of T-cadherin expression on B16F10 melanoma cells.

Melanoma is one of the most deadly skin cancers. T-cadherin is an atypical member of the cadherin superfamily as it lacks the transmembrane and cytoplasmic domains and is anchored to cell membranes through glycosylphosphatidylinositol (GPI) anchors. T-cadherin downregulation is associated with a poorer prognosis in various carcinomas, such as lung, ovarian, cervical and prostate cancer, while in the majority of cancer cell lines, T-cadherin re-expression inhibits cell proliferation and invasiveness, increases susceptibility in apoptosis and reduces tumor growth in in vivo models. The functional relevance of T-cadherin gene expression in melanoma progression remains to be clarified. The present study was designed for this purpose. The T-cadherin gene was transfected into B16F10 melanoma cells to express T-cadherin in the cells which were originally deficient in T-cadherin expression. The proliferation, invasiveness, apoptosis and cell cycle of the transfected B16F10 melanoma cells were analyzed. The present study showed that the expression of T-cadherin in B16F10 melanoma cells markedly reduced cell proliferation and permeation through Matrigel-coated membranes, representing invasiveness. The percentage of early apoptotic cells and cells in the G2/M phase of the cell cycle was markedly increased compared with either parental B16F10 (without transfection) or empty pEGFP-N1 (without T-cadherin gene)-transfected B16F10 cells, suggesting G2/M arrest, with similarity between the parental and empty pEGFP-N1-transfected B16F10 cells. T-cadherin is important in melanoma progression and may be a possible target for therapy in melanoma and certain other types of cancer.

Ganoderma lucidum polysaccharides counteract inhibition on CD71 and FasL expression by culture supernatant of B16F10 cells upon lymphocyte activation.

Immune responses to tumor-associated antigens are often detectable in tumor-bearing hosts, but they fail to eliminate malignant cells or prevent development of metastases. Tumor cells produce factors such as interleukin-10, transforming growth factor-ß1 and vascular endothelial growth factor (VEGF) that suppress the function of immune cells or induce apoptosis of immune cells. Culture supernatant of tumor cells may contain these immunosuppressive factors which suppress lymphocyte activation. CD71 and FasL are two important molecules that are expressed upon lymphocyte activation. Counteraction against suppression CD71 and FasL expression upon lymphocyte activation may benefit tumor control. A potential component with this effect is Ganoderma lucidum polysaccharides (Gl-PS). In this study, Gl-PS was used on lymphocytes incubating with culture supernatant of B16F10 melanoma cells (B16F10-CS) in the presence of phytohemagglutinin. Following induction with phytohemagglutinin, B16F10-CS suppressed CD71 expression in lymphocytes (as detected by immunofluorescence and flow cytometry), proliferation in lymphocytes (as detected by MTT assay), and FasL expression in lymphocytes (as detected by immunocytochemistry and western blot analysis), while Gl-PS fully or partially counteracted these suppressions. Gl-PS showed counteractive effects against suppression induced by B16F10-CS on CD71 and FasL expression upon lymphocyte activation, suggesting the potential of Gl-PS to facilitate cancer immunotherapy.

Enhanced MHC class I and costimulatory molecules on B16F10 cells by Ganoderma lucidum polysaccharides.

PURPOSE: It is obvious that malignant cells evade from immune system in patients with manifest malignancy. Deficient major histocompatibility complex (MHC) class I and costimulatory molecules on malignant cells partially consist of evasion strategy since antigen bond MHC and costimulatory molecules provide two signals necessary for T cell activation. Therefore, enhancement of MHC-I and costimulatory molecules may favor restraint of the evasion. For this purpose, Ganoderma lucidum Polysaccharides (Gl-PS) was used on B16F10 melanoma cells in this study. METHODS: Immunocytochemistry and flowcytometry were used to determine the H-2K(b) and H-2D(b) (two prominent MHC class I molecules in C57BL mouse) as well as B7-1 and B7-2 (two prominent costimulatory molecules) expression on B16F10 cells after incubation with Gl-PS, while messenger ribonucleic acid (mRNA) of these molecules was detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The H-2K(b) and H-2D(b), and B7-1 and B7-2 on B16F10 cells and mRNAs of these molecules were enhanced by Gl-PS, and more efficient antitumor cytotoxicity was induced by the Gl-PS treated cells. CONCLUSIONS: The MHC class I molecules and costimulatory molecules may be enhanced by Gl-PS, and more efficient immune cell mediated cytotoxicity against these B16F10 cells may be induced, which may favor cancer therapy.

Ganoderma lucidum polysaccharides antagonize the suppression on lymphocytes induced by culture supernatants of B16F10 melanoma cells.

OBJECTIVES: Tumour cells produce factors such as interleukin 10 (IL-10), transforming growth factor ß1 (TGF-ß1) and vascular endothelial growth factor (VEGF) that suppress the function of immune cells or induce apoptosis of immune cells. One of the most important goals of tumour immunotherapy is to antagonize this suppression on immune cells. Ganoderma lucidum polysaccharides (Gl-PS) may have this potential. The purpose of this study was to determine the antagonistic effects of Gl-PS on the suppression induced by B16F10 melanoma cell culture supernatant (B16F10-CS) on lymphocytes. METHODS: Gl-PS was used on lymphocytes incubated with B16F10-CS. Enzyme-linked immunosorbent assay was used to determine the levels of IL-10, TGF-ß1 and VEGF in B16F10-CS. The MTT assay was used to determine the proliferation of lymphocytes. Immunocytochemistry and Western blot assay were used to determine perforin and granzyme B production in lymphocytes. KEY FINDINGS: There were elevated levels of IL-10, TGF-ß1 and VEGF in B16F10-CS. The lymphocyte proliferation, and perforin and granzyme B production in lymphocytes after induction with phytohemagglutinin, as well as lymphocyte proliferation in the mixed lymphocyte reaction, were suppressed by B16F10-CS. This suppression was fully or partially antagonized by Gl-PS. CONCLUSIONS: B16F10-CS suppressed lymphocyte proliferation and perforin and granzyme B production in lymphocytes after induction with phytohemagglutinin, as well as lymphocyte proliferation in the mixed lymphocyte reaction. This suppression may be associated with elevated levels of immunosuppressive IL-10, TGF-ß1 and VEGF in B16F10-CS. Gl-PS had antagonistic effects on the immunosuppression induced by B16F10-CS, suggesting the potential for Gl-PS in cancer immunotherapy.

Promoting effects of Ganoderma lucidum polysaccharides on B16F10 cells to activate lymphocytes.

The immune system in patients with cancer often fails to control tumour growth because of deficient immunogenicity of tumour cells. Ganoderma lucidum polysaccharides (Gl-PS) are believed to have anti-tumour effects by boosting host immune function. Additionally, Gl-PS may have some direct effects on tumour cells in the activation of lymphocytes, thus enhancing the immunogenicity of tumour cells. We tested the effects of Gl-PS in lymphocyte activation by incubating Gl-PS with a tumour cell line deficient in antigen presentation. Our study showed that Gl-PS can promote B16F10 melanoma cells to induce lymphocyte proliferation, CD69 and FasL expression and IFN-γ production, indicating that Gl-PS can improve the nature of B16F10 cells to activate lymphocytes. Furthermore, H-2D(b) [a major histocompatibility (MHC) class I molecule], and B7-1 and B7-2 (two prominent co-stimulatory molecules expressed on B16F10 cells) were enhanced by Gl-PS, suggesting that these molecules may at least partially be involved in the process of Gl-PS on B16F10 cells to activate lymphocytes.