BACKGROUND: Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens. METHODS: Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ. RESULTS: This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival. CONCLUSION P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide ; Humans ; Glioblastoma/drug therapy* ; Animals ; Mice ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics* ; YAP-Signaling Proteins ; Hydroxylation ; Dacarbazine/pharmacology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Collagen/biosynthesis* ; Collagen Type I/metabolism* ; Prolyl Hydroxylases/metabolism* ; Antineoplastic Agents, Alkylating/therapeutic use*

OBJECTIVE: To establish a mouse model bearing orthotopic temozolomide (TMZ)-resistant glioma that mimics the development of drug resistance in gliomas METHODS: Seventy-eight adult C57BL/6 mice were randomly divided into 6 groups ( RESULTS: The mouse models bearing TMZresistant glioma was successfully established. The cells from the high-dose induced group showed a significantly higher colony-forming rate than those from the high-dose control group ( CONCLUSIONS Progressive increase of TMZ doses in mice bearing orthotopic gliomas can effectively induce TMZ resistance of the gliomas.
Animals ; Antineoplastic Agents, Alkylating/pharmacology* ; Brain Neoplasms/drug therapy* ; Cell Line, Tumor ; Disease Models, Animal ; Drug Resistance, Neoplasm ; Glioma/drug therapy* ; Mice ; Mice, Inbred C57BL ; Temozolomide/therapeutic use*

Animals ; Antineoplastic Agents, Alkylating/pharmacology* ; Breast Neoplasms/drug therapy* ; Cell Line ; Cell Line, Tumor ; Cyclophosphamide/pharmacology* ; Ginkgo biloba/chemistry* ; Mammary Neoplasms, Animal/drug therapy* ; Mice ; Plant Extracts/administration & dosage*

OBJECTIVE: To investigate the effect of triptolide (TP) on oxidative stress and apoptosis in TM4 sertoli cells and related molecular mechanism. METHODS: TM4 cells were incubated with different concentrations of triptolide for 24 h, then collected for further experiments. Cell proliferation analysis was used to measure the inhibitive effect of triptolide on proliferation of TM4 cells; DCFH-DA (6-carboxy-2',7'-dichlorofluorescein diacetate) probe was used to stain the TM4 cells, the level change of intracellular ROS was discovered through flow cytometry; the TM4 cells were stained by Annexin V-FITC/PI to detect whether triptolide induced apoptosis in the TM4 cells; Protein was extracted from the TM4 cells in control and triptolide group. Western blot was performed to determine the expression of apoptosis marker protein cleaved-PARP and PI3K/Akt signaling pathway-related proteins [p-Akt (Ser473), Akt, p-mTOR (Ser2448), mTOR, p-p70S6K (Thr389), p70S6K]. RESULTS: Cell proliferation analysis revealed that triptolide reduced the TM4 cells viability significantly compared with control group in a dosage-dependent manner [10 nmol/L: (73.77±20.95)%, 100 nmol/L: (51.60±10.43)%, 500 nmol/L: (44.34±5.78)%]; The level of intracellular ROS in the TM4 cells was significantly induced in a dosage-dependent manner (P<0.01); triptolide remarkably induced early-stage and late-stage apoptosis in the TM4 cells [control: (3.84±1.50)%, 100 nmol/L: (13.04±2.03)%, 200 nmol/L: (16.24±1.34)%, 400 nmol/L: (18.76±3.45)%]; The expression of cleaved-PARP was significantly upregulated in the TM4 cells after incubation with triptolide (P<0.01); The expression levels of p-Akt/Akt and p-p70S6K/p70s6k were significantly increased compared with control group (P<0.01). No significant change was observed among the expression levels of p-mTOR/mTOR (P>0.05). CONCLUSION In vitro studies showed that triptolide could effectively suppress the proliferation and induce apoptosis of TM4 sertoli cells. The oxidative stress was upregulated after incubation with triptolide, which may be one of the mechanisms of cytotoxicity in TM4 cells. Treatment of triptolide led to activation of Akt and p70S6K, indicating that the PI3K/Akt signaling pathway may be involved in response to oxidative stress in TM4 cells. The activation of PI3K/Akt signaling pathway was one of the molecular mechanisms involved in triptolide-mediated oxidative stress in TM4 cells. Our study provides insight into alleviating reproductive toxicity of triptolide in clinical and developing male contraceptive.
Antineoplastic Agents, Alkylating/pharmacology* ; Apoptosis/drug effects* ; Diterpenes/pharmacology* ; Epoxy Compounds/pharmacology* ; Humans ; Male ; Oxidative Stress/drug effects* ; Phenanthrenes/pharmacology* ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt/drug effects* ; Sertoli Cells/drug effects* ; Signal Transduction/drug effects*

Although methyltransferase has been recognized as a major element that governs the epigenetic regulation of the genome during temozolomide (TMZ) chemotherapy in glioblastoma multiforme (GBM) patients, its regulatory effect on glioblastoma chemoresistance has not been well defined. This study investigated whether DNA methyltransferase (DNMT) expression was associated with TMZ sensitivity in glioma cells and elucidated the underlying mechanism. DNMT expression was analyzed by western blotting. miR-20a promoter methylation was evaluated by methylation-specific PCR. Cell viability and apoptosis were assessed using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and TdT-mediated dUTP-biotin nick end labeling assays, respectively. The results showed that compared with parental U251 cells, DNMT1 expression was downregulated, miR-20a promoter methylation was attenuated and miR-20a levels were elevated in TMZ-resistant U251 cells. Methyltransferase inhibition by 5-aza-2\'-deoxycytidine treatment reduced TMZ sensitivity in U251 cells. In U251/TM cells, DNMT1 expression was negatively correlated with miR-20a expression and positively correlated with TMZ sensitivity and leucine-rich repeats and immunoglobulin-like domains 1 expression; these effects were reversed by changes in miR-20a expression. DNMT1 overexpression induced an increase in U251/TM cell apoptosis that was inhibited by the miR-20a mimic, whereas DNMT1 silencing attenuated U251/TM cell apoptosis in a manner that was abrogated by miR-20a inhibitor treatment. Tumor growth of the U251/TM xenograft was inhibited by pcDNA-DNMT1 pretreatment and boosted by DNMT1-small hairpin RNA pretreatment. In summary, DNMT1 mediated chemosensitivity by reducing methylation of the microRNA-20a promoter in glioma cells.
Animals ; Antineoplastic Agents, Alkylating/*pharmacology/therapeutic use ; Apoptosis/drug effects ; Brain/drug effects/metabolism/pathology ; Brain Neoplasms/drug therapy/*genetics/pathology ; DNA (Cytosine-5-)-Methyltransferase/antagonists & inhibitors/*genetics/metabolism ; DNA Methylation ; Dacarbazine/*analogs & derivatives/pharmacology/therapeutic use ; Drug Resistance, Neoplasm ; Female ; Gene Expression Regulation, Neoplastic ; Glioma/drug therapy/*genetics/pathology ; Humans ; Mice, Inbred C57BL ; MicroRNAs/*genetics ; Promoter Regions, Genetic

Epithelial ovarian cancer (OC) is a common gynecologic malignancy in women. The standard treatment for OC is maximal cytoreductive surgical debulking followed by platinum-based chemotherapy. Despite the high response rate to primary therapy, approximately 85% of patients will develop recurrent ovarian cancer (ROC). This review identifies the clinical use of trabectedin in the treatment algorithm for ROC, with specific emphasis on platinum-sensitive ROC, for which trabectedin in combination with pegylated liposomal doxorubicin has been approved as a treatment protocol. The main mechanisms of action of trabectedin at the cellular level and in the tumor microenvironment is also discussed as bases for identifying biomarkers for selecting patients who may largely benefit from trabectedin-based therapies.
Antineoplastic Agents, Alkylating ; therapeutic use ; Clinical Trials as Topic ; DNA Damage ; Dioxoles ; administration & dosage ; pharmacology ; therapeutic use ; Doxorubicin ; administration & dosage ; analogs & derivatives ; Female ; Humans ; Neoplasm Recurrence, Local ; drug therapy ; Neoplasms, Glandular and Epithelial ; drug therapy ; Ovarian Neoplasms ; drug therapy ; Polyethylene Glycols ; administration & dosage ; Tetrahydroisoquinolines ; administration & dosage ; pharmacology ; therapeutic use ; Tumor Microenvironment

In the present study, the effects of Pleurotus nebrodensis polysaccharide (PN-S) on the immune functions of immunosuppressed mice were determined. The immunosuppressed mouse model was established by treating the mice with cyclophosphamide (40 mg/kg/2d, CY) through intraperitoneal injection. The results showed that PN-S administration significantly reversed the CY-induced weight loss, increased the thymic and splenic indices, and promoted proliferation of T lymphocyte, B lymphocyte, and macrophages. PN-S also enhanced the activity of natural killer cells and increased the immunoglobulin M (IgM) and immunoglobulin G (IgG) levels in the serum. In addition, PN-S treatment significantly increased the phagocytic activity of mouse peritoneal macrophages. PN-S also increased the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), and nitric oxide (NOS) in splenocytes. qRT-PCR results also indicated that PN-S increased the mRNA expression of IL-6, TNF-α, INF-γ, and nitric oxide synthase (iNOS) in the splenocytes. These results suggest that PN-S treatment enhances the immune function of immunosuppressed mice. This study may provide a basis for the application of this fungus in adjacent immunopotentiating therapy against cancer and in the treatment of chemotherapy-induced immunosuppression.
Animals ; Antineoplastic Agents, Alkylating ; Biological Products ; pharmacology ; therapeutic use ; Cell Line ; Cyclophosphamide ; Immunity ; drug effects ; Immunologic Factors ; pharmacology ; therapeutic use ; Immunosuppression ; Interferon-gamma ; metabolism ; Interleukin-6 ; metabolism ; Macrophages ; drug effects ; metabolism ; Male ; Mice, Inbred BALB C ; Neoplasms ; drug therapy ; immunology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Phagocytosis ; drug effects ; Pleurotus ; chemistry ; Polysaccharides ; pharmacology ; therapeutic use ; Tumor Necrosis Factor-alpha ; metabolism

O6-methylguanine DNA methyltransferase (MGMT) can remove DNA alkylation adducts, thereby repairing damaged DNA and contributing to the drug resistance of gliomas to alkylating agents. In addition, glioma stem-like cells (GSCs) have been demonstrated to be involved in the recurrence and treatment resistance of gliomas. In this study, we aimed to investigate MGMT expression and regulatory mechanisms in GSCs and the association of MGMT with temozolomide (TMZ) sensitivity. GSCs were enriched from one MGMT-positive cell line (SF-767) and 7 MGMT-negative cell lines (U251, SKMG-4, SKMG-1, SF295, U87, MGR1, and MGR2) through serum-free clone culture. GSCs from the U251G, SKMG-4G, SF295G, and SKMG-1G cell lines became MGMT-positive, but those from the U87G, MGR1G, and MGR2G cell lines remained MGMT-negative. However, all the GSCs and their parental glioma cell lines were positive for nuclear factor-κB (NF-κB). In addition, GSCs were more resistant to TMZ than their parental glioma cell lines (P < 0.05). However, there was no significant difference in the 50% inhibition concentration (IC50) of TMZ between MGMT-positive and MGMT-negative GSCs (P > 0.05). When we treated the MGMT-positive GSCs with TMZ plus MG-132 (an NF-κB inhibitor), the antitumor activity was significantly enhanced compared to that of GSCs treated with TMZ alone (P <0.05). Furthermore, we found that MGMT expression decreased through the down-regulation of NF-κB expression by MG-132. Our results show that MG-132 may inhibit NF-κB expression and further decrease MGMT expression, resulting in a synergistic effect on MGMT-positive GSCs. These results indicate that enhanced MGMT expression contributes to TMZ resistance in MGMT-positive GSCs.
Antineoplastic Agents, Alkylating ; pharmacology ; Cell Line, Tumor ; Dacarbazine ; analogs & derivatives ; pharmacology ; Drug Resistance, Neoplasm ; Drug Synergism ; Glioma ; metabolism ; pathology ; Humans ; Leupeptins ; pharmacology ; NF-kappa B ; antagonists & inhibitors ; metabolism ; Neoplastic Stem Cells ; metabolism ; O(6)-Methylguanine-DNA Methyltransferase ; metabolism

This study is to investigate the anti-tumor activities of a novel cyclophosphamide derivate 4, 6-diphenyl cyclophosphamide (9b) in vivo and in vitro, and its possible mechanism of action. The inhibitory effects of 9b on human hepatoma cell line HepG2, human breast carcinoma cell line MCF-7 and human myeloid leukemia cell line K562 were measured by MTT assay in vitro. Cell cycle distribution and apoptotic rate were evaluated by flow cytometry. To evaluate the anti-tumor effect of 9b in vivo, mouse model bearing inoculated H22 tumor was established. The results indicated that 9b could inhibit the proliferation of HepG2, MCF-7 and K562 cells in a dose and time dependent manner. The ICo50 values of 9b were 32.34 micromol.L-1 to HepG2 cells, 87.07 micromol.L-1 to MCF-7 cells and 149.10 micromol.L-1 to K562 cells after incubation for 48 h. The results of flow cytometry indicated that after being treated for 48 h with different concentrations of 9b, the ratios of HepG2, MCF-7 cells at the Go/G1 phase and K562 cells at the G0/Gl phase and G2/M phase increased significantly compared with control group, and the apoptotic rate increased with the increase of the concentration of 9b. 9b could significantly reduce tumor weight of H22 solid tumor mouse model in vivo. To summarize, 9b showed significantly anti-tumor activity in vivo and in vitro, of which the mechanism might be associated with the change of cell cycle distribution and induction of tumor cell apoptosis.
Animals ; Antineoplastic Agents, Alkylating ; chemistry ; pharmacology ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclophosphamide ; analogs & derivatives ; chemistry ; pharmacology ; Dose-Response Relationship, Drug ; Female ; Humans ; Inhibitory Concentration 50 ; Liver Neoplasms, Experimental ; pathology ; Male ; Mice ; Molecular Structure ; Random Allocation ; Tumor Burden ; drug effects

Cyclophosphamide (CPA) is the most common alkylating antineoplastic agent, as well as a strong immunosuppressant that is frequently applied to autoimmune diseases and organ transplantation. It is metabolized by cytochrome P450 oxidases (CYPs) to its active metabolite which played a critical role in therapy. CPA has serious and even fatal side effects, and its efficacy and adverse reactions are significantly varied among individuals. In this review, the association of the genetic polymorphisms in the metabolic enzymes and transporters involved in the disposition of CPA with the efficacy and adverse effects of CPA were summarized, thereby providing fundamental reference for further pharmacogenomic study of CPA.
Antineoplastic Agents, Alkylating ; pharmacology ; Cyclophosphamide ; pharmacology ; Humans ; NADPH-Ferrihemoprotein Reductase ; metabolism ; Pharmacogenetics