A series of chemotherapeutic drugs that induce DNA damage, such as cisplatin (DDP), are standard clinical treatments for ovarian cancer, testicular cancer, and other diseases that lack effective targeted drug therapy. Drug resistance is one of the main factors limiting their application. Sensitizers can overcome the drug resistance of tumor cells, thereby enhancing the antitumor activity of chemotherapeutic drugs. In this study, we aimed to identify marketable drugs that could be potential chemotherapy sensitizers and explore the underlying mechanisms. We found that the alcohol withdrawal drug disulfiram (DSF) could significantly enhance the antitumor activity of DDP. JC-1 staining, propidium iodide (PI) staining, and western blotting confirmed that the combination of DSF and DDP could enhance the apoptosis of tumor cells. Subsequent RNA sequencing combined with Gene Set Enrichment Analysis (GSEA) pathway enrichment analysis and cell biology studies such as immunofluorescence suggested an underlying mechanism: DSF makes cells more vulnerable to DNA damage by inhibiting the Fanconi anemia (FA) repair pathway, exerting a sensitizing effect to DNA damaging agents including platinum chemotherapy drugs. Thus, our study illustrated the potential mechanism of action of DSF in enhancing the antitumor effect of DDP. This might provide an effective and safe solution for combating DDP resistance in clinical treatment.
Female ; Male ; Humans ; Cisplatin/pharmacology* ; Disulfiram/pharmacology* ; Testicular Neoplasms/drug therapy* ; Fanconi Anemia/drug therapy* ; Alcoholism/drug therapy* ; Drug Resistance, Neoplasm ; Cell Line, Tumor ; Substance Withdrawal Syndrome/drug therapy* ; Apoptosis ; Antineoplastic Agents/therapeutic use* ; Cell Proliferation

OBJECTIVETo investigate the reverse effect of mutidrug resistance of curcumin combined with melphalan on the mutidrug-resistant human multiple myeloma cell line MOLP-2/R and the relation with FA/BRCA pathway.

METHODSThe inhibitory effects of the drugs on the growth of MOLP-2/R cells were determined by MTT assay. Cell cycle analysis, intracellular drug concentration and apoptosis were assayed by flow cytometry. The expression of FANCD2 monoubiquitination was determined by Western blot analysis.

RESULTSCo-administration of curcumin and melphalan had an synergistic inhibitory effects on the proliferation, IC50 of melphalan with 10 micromol/L curcumin reduced from 45.5 micromol/L to 19 micromol/L in MOLP-2/R cells. The apoptosis percentage of MOLP-2/R cells was significantly increased from (23.3 +/- 0.6)% to (52.6% +/- 0.8)% by the treatment of melphalan 20 micromol/L plus curcumin 10 micromol/L with the increased percentage of cells in the G2/M phase (from 9.1% to 18.5%) and enhanced intracellular drug concentration of MOLP-2/ R cells (from 15.2 +/- 0.3 to 21.4 +/- 0.8 ). The effects were accompanied with inhibition of FA/BRCA pathway by down regulation of FANCD2 protein monoubiquitination.

CONCLUSIONCurcumin combined with melphalan results in synergistic effects and reverses multiple drug resistance of MOLP-2/R cells effectively. The inhibition of FA/BRCA pathway may be the mechanism.

Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Curcumin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; drug effects ; Fanconi Anemia Complementation Group D2 Protein ; metabolism ; Humans ; Multiple Myeloma ; drug therapy ; metabolism ; pathology

Acute myeloid leukemia (AML) is a heterogeneous malignancy that comprises 25-30% of pediatric leukemias in Korea. Several inherited diseases, such as Down syndrome and Fanconi anemia, predispose towards AML leukemogenesis. Subgrouping of AML is a key diagnostic step, previously done with the French-American-British (FAB) classification and recently complemented by that of the World Health Organization (WHO). An important feature of AML is the possibility of chloroma at diagnosis, which, if detected, requires follow-up evaluation to determine treatment response. Numerous genetic abnormalities with prognostic relevance have recently been found, the most important of which include those of the core-binding factor (CBF) leukemias, and FLT3-ITD mutation. These genetic abnormalities, combined with patient response to initial treatment, allow for a scheme of risk stratification, and the current consensus is to treat low risk patients with chemotherapy only, whereas high risk patients may receive allogeneic transplant in first remission, although the benefits of transplant remain inconclusive. Overall, the outcome of children and adolescents with AML has improved significantly so that many clinical trials now report event-free survival of around 60%. However, much of this improvement stems from better supportive care and transplant methods, and the genetics-based diagnostic advances in AML have yet to result in enhanced treatment. New therapeutics, including possibly targeted therapy, are necessary to further improve the outcome of pediatric AML.
Adolescent ; Child ; Classification ; Complement System Proteins ; Consensus ; Core Binding Factors ; Diagnosis ; Disease-Free Survival ; Down Syndrome ; Drug Therapy ; Fanconi Anemia ; Humans ; Korea ; Leukemia ; Leukemia, Myeloid, Acute ; Sarcoma, Myeloid ; World Health Organization

OBJECTIVETo investigate the effect of PARP1 inhibitor PJ34 on multi-drug resistance in a human multiple myeloma cell line and its connection with FA/BRCA pathway in DNA damage repair.

METHODSA CCK8 assay was used to measure the inhibition rate. Real-time quantitative PCR was used to detect expression changes of DNA repair genes involved in the FA/BRCA pathway. Western blotting assay was used to detect expression of key protein FANCD2 in the FA/BRCA pathway. Annexin VFITC/PI double staining flow cytometry was used to measure cell apoptosis induced by PJ34. A COMET assay was used to detect the effect of PJ34 on DNA damage repair.

RESULTSPJ34 could significantly enhance the sensitivity of RPMI8226/R cells to melphalan. The IC50 value of melphalan was dropped from 20.43 mol/L to 7.8 mol/L. PJ34 could inhibit the DNA damage repair, and the effect was related with the inhibition of FA/BRCA pathway. PJ34 and melphalan showed a synergistic effect in promoting the apoptosis of RPMI8226/R cells.

CONCLUSIONPJ34 can reverse the resistance of RPMI8226/R cells to melphalan by inhibiting the FA/BRCA pathway, which in turn can induce suppression of DNA damage repair. Therefore, PJ34 may have clinical value in overcoming the multi-drug resistance of multiple myeloma.

Antineoplastic Agents ; pharmacology ; BRCA2 Protein ; genetics ; metabolism ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Fanconi Anemia Complementation Group D2 Protein ; genetics ; metabolism ; Humans ; Multiple Myeloma ; drug therapy ; enzymology ; genetics ; metabolism ; Phenanthrenes ; pharmacology ; Poly (ADP-Ribose) Polymerase-1 ; Poly(ADP-ribose) Polymerase Inhibitors ; Poly(ADP-ribose) Polymerases ; genetics ; metabolism