A 1,2,3-Triazole Derivative of Quinazoline Exhibits Antitumor Activity by Tethering RNF168 to SQSTM1/P62.

Quinazoline and its derivatives have drawn much attention in the development of potential antitumor agents. Here, we synthesized a series of 1,2,3-triazole derivatives of quinazoline at the C6 position and evaluated for their cytotoxic activity in various human cancer cell lines. We found that compound 5a was the most cytotoxic to HCT-116 cells (IC50, 0.36 µM). Target profiling found that 5a directly binds to both the autophagy-associated protein SQSTM1/P62 and the E3 ligase RNF168, promoting their interaction. Consistently, 5a treatment induces a decrease in RNF168-mediated H2A ubiquitination and compromises homologous recombination-mediated DNA repair, thus increasing the sensitivity of HCT-116 to X-ray radiation. Moreover, 5a suppressed xenografted tumor growth in mice in a dose-dependent manner. Taken together, the 1,2,3-triazole derivative of quinazoline 5a may serve as a novel compound for tumor therapy based on its role in promoting a P62/RNF168 interaction.

Pharmacological Activating Transcription Factor 6 Activation Is Beneficial for Liver Retrieval With ex vivo Normothermic Mechanical Perfusion From Cardiac Dead Donor Rats.

Background: Normothermic machine perfusion (NMP) could be beneficial for organ retrieval from donors after cardiac death (DCD). Activating transcription factor 6 (ATF6) was recently shown to mitigate liver ischemia/reperfusion injury and confer protection. The aims of this study were to assess the implication of ATF6 in liver retrieval from DCD rat livers with NMP and explore the effect of pharmacologic ATF-6 activation on liver retrieval. Methods: The livers from DCD rats were exposed to 30 min of warm ischemia and 8 h cold preservation followed by 2 h NMP with or without an ATF6 activator in the perfusate. Perfusates and livers were harvested to detect ATF6 expression, liver function, and inflammation. Results: DCD livers with NMP were associated with ATF6 overexpression and activation based on IHC and WB (P < 0.05). The ATF6 activator downregulated perfusate aminotransferases, decreased the Suzuki score, downregulated CD68 and MPO based on IHC, induced the expression of cytochrome c in mitochondria and inhibited the expression of cytochrome c in cytoplasm based on WB, reduced TNFα and IL-6 levels based on ELISA, decreased levels of MDA, GSSG and ATP, and increased SOD activity and GSH levels in the perfused livers (P < 0.05). Conclusion: ATF6 is important for liver retrieval, and an exogenous ATF6 activator accelerates liver retrieval from DCD rats in an ex vivo NMP model.

ASPM promotes homologous recombination-mediated DNA repair by safeguarding BRCA1 stability.

DNA double-strand break (DSB) repair by homologous recombination (HR) is essential for ensuring genome stability. Abnormal spindle-like microcephaly-associated (ASPM) gene encodes a spindle protein that is commonly implicated in primary microcephaly. We found that ASPM is recruited to sites of DNA damage in a PARP2-dependent manner. ASPM interacts with BRCA1 and its E3 ligase HERC2, preventing HERC2 from accessing to BRCA1 and ensuring BRCA1 stability. Inhibition of ASPM expression promotes HERC2-mediated BRCA1 degradation, compromises HR repair efficiency and chromosome stability, and sensitizes cancer cells to ionizing radiation. Moreover, we observed a synergistic effect between ASPM and PARP inhibition in killing cancer cells. This research has uncovered a novel function for ASPM in facilitating HR-mediated repair of DSBs by ensuring BRCA1 stability. ASPM might constitute a promising target for synthetic lethality-based cancer therapy.

Interaction analysis of gene variants related to one-carbon metabolism with chronic hepatitis B infection in Chinese patients.

BACKGROUND: The risk of chronic hepatitis B (CHB) infection is influenced by aberrant DNA methylation and altered nucleotide synthesis and repair, possibly caused by polymorphic variants in one-carbon metabolism genes. In the present study, we investigated the relationship between polymorphisms belonging to the one-carbon metabolic pathway and CHB infection. METHODS: A case-control study using 230 CHB patients and 234 unrelated healthy controls was carried out to assess the genetic association of 24 single nucleotide polymorphisins (SNPs) determined by mass spectrometry. RESULTS: Three SNPs, comprising rs10717122 and rs2229717 in serine hydroxymethyltransferase1/2 (SHMT2) and rs585800 in betaine-homocysteine S-methyltransferase (BHMT), were associated with the risk of CHB. Patients with DEL allele, DEL.DEL and DEL.T genotypes of rs10717122 had a 1.40-, 2.00- and 1.83-fold increased risk for CHB, respectively. Cases inheriting TA genotype of rs585800 had a 2.19-fold risk for CHB infection. The T allele of rs2229717 was less represented in the CHB cases (odds ratio = 0.66, 95% confidence interval = 0.48-0.92). The T allele of rs2229717 was less in patients with a low hepatitis B virus-DNA level compared to the control group (odds ratio = 0.49, 95% confidence interval = 0.25-0.97) and TT genotype of rs2229717 had a significant correlation with hepatitis B surface antigen level (p = 0.0195). Further gene-gene interaction analysis showed that subjects carrying the rs10717122 DEL.DEL/DEL.T and rs585800 TT/TA genotypes had a 2.74-fold increased risk of CHB. CONCLUSIONS: The results of the present study suggest that rs10717122, rs585800 and rs2229717 and gene-gene interactions of rs10717122 and rs585800 affect the outcome of CHB infection, at the same time as indicating their usefulness as a predictive and diagnostic biomarker of CHB infection.

Six-Transmembrane Epithelial Antigen of the Prostate 3 Deficiency in Hepatocytes Protects the Liver Against Ischemia-Reperfusion Injury by Suppressing Transforming Growth Factor-ß-Activated Kinase 1.

BACKGROUND AND AIMS: Hepatic ischemia-reperfusion (I/R) injury remains a major challenge affecting the morbidity and mortality of liver transplantation. Effective strategies to improve liver function after hepatic I/R injury are limited. Six-transmembrane epithelial antigen of the prostate 3 (Steap3), a key regulator of iron uptake, was reported to be involved in immunity and apoptotic processes in various cell types. However, the role of Steap3 in hepatic I/R-induced liver damage remains largely unclear. APPROACH AND RESULTS: In the present study, we found that Steap3 expression was significantly up-regulated in liver tissue from mice subjected to hepatic I/R surgery and primary hepatocytes challenged with hypoxia/reoxygenation insult. Subsequently, global Steap3 knockout (Steap3-KO) mice, hepatocyte-specific Steap3 transgenic (Steap3-HTG) mice, and their corresponding controls were subjected to partial hepatic warm I/R injury. Hepatic histology, the inflammatory response, and apoptosis were monitored to assess liver damage. The molecular mechanisms of Steap3 function were explored in vivo and in vitro. The results demonstrated that, compared with control mice, Steap3-KO mice exhibited alleviated liver damage after hepatic I/R injury, as shown by smaller necrotic areas, lower serum transaminase levels, decreased apoptosis rates, and reduced inflammatory cell infiltration, whereas Steap3-HTG mice had the opposite phenotype. Further molecular experiments showed that Steap3 deficiency could inhibit transforming growth factor-ß-activated kinase 1 (TAK1) activation and downstream c-Jun N-terminal kinase (JNK) and p38 signaling during hepatic I/R injury. CONCLUSIONS: Steap3 is a mediator of hepatic I/R injury that functions by regulating inflammatory responses as well as apoptosis through TAK1-dependent activation of the JNK/p38 pathways. Targeting hepatocytes, Steap3 may be a promising approach to protect the liver against I/R injury.

Synthesis and cytotoxic activity of chalcone analogues containing a thieno[2,3-d]pyrimidin-2-yl group as the A-ring or B-ring.

Many natural or synthetic chalcones have potential anti-tumor activity. Here, we synthesized two series of chalcone analogues containing a thieno[2,3-d]pyrimidin-2-yl group and evaluated for their cytotoxic activity towards cultured human lung cancer A549 and colorectal HCT-116 cells. Among them, compound 8d was the most cytotoxic against HCT-116 cells, with an IC50 value of 2.65 µM. Analyses of the phenotypic changes induced by this compound found a dose-dependent accumulation of HCT-116 cells in sub-G1 phase, indicating that compound 8d might induce apoptosis. Furthermore, we found that 8d triggered mitochondrial membrane potential depolarization, promoted reactive oxygen species formation in HCT-116 cells, and increased the percentage of early and late apoptotic cells. Finally, immunoblotting indicated that 8d increased PARP-1 and caspases 3, 7 and 9 cleavage. These data suggest that compound 8d induces apoptosis via the mitochondrial death pathway.

Synthesis, cytotoxic evaluation and target identification of thieno[2,3-d]pyrimidine derivatives with a dithiocarbamate side chain at C2 position.

Two series of thieno[2,3-d]pyrimidine derivatives bearing a dithiocarbamate side chain at the C2 position were synthesized and evaluated for cytotoxic activity in human lung cancer A549 and colon cancer HCT-116 cell lines. Compound 3n exhibited the most cytotoxic effect on A549 cells with an IC50 value of 4.87 µM, inducing a cell cycle arrest at G2/M phase and activating the spindle assembly checkpoint (SAC). To identify the target protein(s) of 3n, we incorporated biotin with 3n through a three-carbon chain and an amide bond to synthesize probe 10. The targeted proteins were pulled down from the A549 total cell lysate by biotin-streptavidin affinity purification and analyzed by mass spectrometry. Tubulin was the only protein identified, which is related to the SAC and directly binds to probe 10 both in vivo and in vitro. Furthermore, compound 3n inhibited tubulin polymerization in vitro in a dose-dependent manner, competed with taxol in binding to tubulin, exerting cytotoxic activity toward taxol-resistant A549 cells. These results demonstrate that thieno[2,3-d]pyrimidine derivative 3n exhibits cytotoxicity in cancer cells by targeting tubulin to activate the SAC and potentially acts as a therapeutic lead compound for taxol-resistant cancers.

Synthesis, crystal structures and antitumor activity of two platinum(II) complexes with methyl hydrazinecarbodithioate derivatives of indolin-2-one.

Two new platinum(II) complexes 7a and 7b with methyl hydrazinecarbodithioate derivatives of indolin-2-one have been prepared and characterized by single-crystal X-ray diffraction, NMR spectroscopy and mass spectrometry. Antiproliferative activity of the two complexes and their ligands 6a and 6b against HCT-116, MCF-7 and MDA-MB-231 cell lines was determined by the MTS assay. Complexes 7a and 7b exhibited stronger antiproliferative activity against three cell lines than compounds 6a and 6b (IC50, 1.89-5.60 versus 6.52-35.13 µM). Moreover, treatment of HCT-116 cells with the complexes resulted in an obvious sub-G1 peak by cell cycle profile analysis, and an increase of cleaved PARP1 and caspases 3, 7, and 9 by immunoblotting analysis. Live cell imaging showed that nucleus shrinkage and condensation started to appear when MCF-7 cells were treated with 7a for 8 h. Fluorescent spectrophotometric analysis revealed that the complexes physically associated with calf thymus DNA. Competitive DNA binding assays uncovered that the complexes non-covalently bind to DNA. Taken together, our results indicated that the two new platinum(II) complexes 7a and 7b non-covalently bind to DNA with high affinity and exhibit cytotoxicity against cancer cells by inducing apoptosis.

Synthesis and antitumor activity evaluation of quinazoline derivatives bearing piperazine-1-carbodithioate moiety at C4-position.

A series of quinazoline derivatives bearing piperazine-1-carbodithioate moiety at the C4-position were synthesized using piperidine and 1-bromo-3-chloropropane as starting materials via eight steps. Final compounds 8a-q and 9a-i were evaluated for their antiproliferative activity against human lung cancer A549, breast adenocarcinoma MCF-7, and colorectal cancer HCT-116 cell lines. The results showed that fourteen of twenty-six final compounds inhibited the proliferation of three cancer cell lines with IC50 values less than 10µM. When treated with a representative compound 8n, HCT-116 cells were arrested at G0/G1 phase of the cell cycle. This provided a clue to further investigation of the mechanism of action.

Synthesis and biological evaluation of quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at C2-position as potential antitumor agents.

A series of quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at the C2-position were synthesized and evaluated for their antiproliferative activities against A549, MCF-7, HeLa, HT29 and HCT-116 cell lines. Most of the synthesized compounds exhibited broad spectrum antitproliferative activity against five cell lines, of which 5c was the most potent against HT29 cell line with an IC50 value of 5.53 µM, inducing a G2/M phase arrest in HT29 cells. Treatment of HT29 cells with 5c resulted in BubR1 phosphorylation and an increase of mitotic index in a time-dependent manner. Furthermore, 5c promoted tubulin polymerization in vitro. These results demonstrate that quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at C2-position may be potentially novel antitumor agents targeting tubulin to activate the spindle assembly checkpoint.

Synthesis and antiproliferative activity of 4-substituted-piperazine-1-carbodithioate derivatives of 2,4-diaminoquinazoline.

A novel series of 4-substituted-piperazine-1-carbodithioate derivatives of 2,4-diaminoquinazoline were synthesized and tested for their antiproliferative activities against five human cancer cell lines including A549 (lung cancer), MCF-7 (breast adenocarcinoma), HeLa (cervical carcinoma), HT29 and HCT-116 (colorectal cancer). Most of the synthesized compounds showed broad spectrum antiproliferative activity (IC50 1.47-11.83 µM), of which 8f, 8m and 8q were the most active members with IC50 values in the range of 1.58-2.27, 1.84-3.27 and 1.47-4.68 µM against five cancer cell lines examined, respectively. Further investigations revealed that compounds 8f, 8m and 8q exhibited weak inhibition against dihydrofolate reductase and no activity against thymidylate synthase, while induced DNA damage and activated the G2/M checkpoint in HCT-116 cells.

Synthesis and antiproliferative evaluation of piperazine-1-carbothiohydrazide derivatives of indolin-2-one.

By varying the substituents (R(1)) at the indolin-2-one scaffold, a series of indolin-2-one derivatives bearing 4-phenylpiperazine-1-carbothiohydrazide moiety at the C3-position were synthesized and evaluated for their antiproliferative activity against three human cancer cell lines. We further selected the 5-chloroindolin-2-one moiety for the extension to another series of compounds by varying the substituents (R(2)) at the phenyl group connected with the piperazine ring. Among all the compounds synthesized, 6d and 6l were most potent with IC50 values of 3.59 and 5.58 µM, respectively against A549 lung cancer cells, while 5f and 6l possessed IC50 values of 3.49 and 4.57 µM, respectively against HCT-116 colon cancer cells which were comparable to that of Sunitinib, an indolin-2-one derivative in cancer therapy.

Synthesis and cytotoxic evaluation of quinazolin-4(3H)-one derivatives bearing thiocarbamate, thiourea or N-methyldithiocarbamate side chains.

We have previously found that the dithiocarbamate derivatives of quinazolin-4(3H)-one could act as cytotoxic agents against a panel of human tumor cell lines. To investigate the contribution of dithiocarbamate moiety to the cytotoxic activity, three series of novel quinazolin-4(3H)-one derivatives bearing thiocarbamate, thiourea or Nmethyldithiocarbamate side chains were synthesized and tested for their cytotoxic activity against human cancer cell lines A549, MCF-7, HeLa, HT29 and HCT-116 by MTT assay. The results showed that transformation of the dithiocarbamate moiety in lead compound I to thiocarbamate or thiourea led to a decrease or loss of cytotoxic activity. Some N-alkylated analogs of lead compound II preferentially inhibited the proliferation of A549 cells, although their potencies were not improved in comparison with the unalkylated counterparts. The structure-activity relationship obtained in this research will be beneficial for further synthesis and discovery of effective cytotoxic agents.

[Methylation and expression of RUNX3 gene promoter in papillary thyroid carcinoma].

OBJECTIVE: To study the relationship between status of methylation of human runt-related transcription factor 3 (RUNX3) gene promoter in papillary thyroid carcinoma (PTC). METHODS: Methylation-specific PCR and immunohistochemical SP technique were used to detect the methylation of RUNX3 gene promoter and expression of its protein in 56 cases of PTC and their matched adjacent non-carcinous epithelium (NCE). RESULTS: In NCE, there was no methylation of RUNX3 gene promoter, while in PTC the methylation rate was 35.7%(20/56), which was related to the tumor TNM stage, pathological grade and lymph node metastasis (P < 0.05). The positive rates of RUNX3 protein expression in NCE and PTC were 100.0% and 60.7%, respectively, with a significant difference (χ(2) = 27.378, P < 0.05). In PTC, the positive rates of RUNX3 protein expression in gradeI and grade II were 70.0% and 37.5%, respectively (P < 0.05); the rates were 46.7% and 76.9% in lymph node metastasis group and no metastasis group, respectively (P < 0.05). Moreover, there was a distinct correlation between methylation of RUNX3 gene promoter and expression of its protein (χ(2) = 21.62, P < 0.01). CONCLUSIONS: Methylation of promoter might be one of the important factors of inactivation of RUNX3 gene, and might play an important role in carcinogenesis and progression of PTC.

[Correlation of mRNA and protein expressions of Runx3 gene in papillary thyroid carcinoma].

OBJECTIVE: To explore the mRNA and protein expressions of Runx3 gene in papillary thyroid carcinoma (PTC). METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the Runx3 mRNA and protein levels in 67 human PTC specimens and their matched adjacent non-cancerous epithelium (NCE). RESULTS: The relative expression value of Runx3 mRNA was 0.31 ± 0.07 in PTC versus 0.92 ± 0.08 in NCE (t = 38.251, P < 0.05). In PTC, it was correlated with the tumor pathological grade and lymph node metastasis (χ(2) = 5.511, 6.492, P < 0.05). The integral optical density value of Runx3 protein confirmed was 1012 ± 221 in PTC versus 1993 ± 199 in NCE (t = 18.413, P < 0.05). In PTC, it was correlated with the tumor TNM stage, pathological grade and lymph node metastasis (χ(2) = 5.550, 9.678, 5.070, P < 0.05). Furthermore there was a distinct correlation between the mRNA and protein expressions of Runx3 gene (χ(2) = 42.699, P < 0.05). CONCLUSION: The mRNA and protein expressions of Runx3 gene in PTC were lower than those in NCE. A lower expression of Runx3 gene may play an important role in the carcinogenesis and progression of PTC.

[Expression of Piwil2 and its relationship with tumor invasion and metastasis in papillary thyroid carcinoma].

OBJECTIVE: To study the expressions of Piwil2 protein and mRNA in papillary thyroid carcinoma (PTC) and the relationship between Piwil2 and the invasion and metastasis of PTC. METHODS: Immunohistochemistry and in situ hybridization were used to detect the expression of Piwil2 protein and mRNA in 60 cases of PTC with the matched adjacent non-cancerous epithelium (NCE). RESULTS: The positive rates of Piwil2 protein expression in PTC and NCE were 88.3% (53/60) and 10.0% (6/60) respectively, with significant difference (χ² = 73.654, P < 0.01). The positive rates of Piwil2 mRNA expression in PTC and NCE were 85.0% (51/60) and 6.7% (4/60) respectively, also with significant difference (χ(2) = 74.148, P < 0.01). Up-regulated expressions of Piwil2 protein and mRNA were related to the invasion and metastasis of PTC (P < 0.05). CONCLUSIONS: Piwil2 may play a role in the invasion and metastasis of PTC.

Synthesis and cytotoxic activity of N-((2-methyl-4(3H)-quinazolinon-6-yl)methyl)dithiocarbamates.

A series of N-((2-methyl-4(3H)-quinazolinon-6-yl)methyl)dithiocarbamates 5a-w were synthesized and evaluated for their cytotoxic activity against five human cancer cell lines. We found that compound 5k inhibited proliferation of A549, MCF-7, HeLa, HT29 and HCT-116 cells with IC(50) values of 5.44, 7.15, 12.16, 10.35 and 11.44 microM, respectively. Compound 5i was the most potent with an IC(50) value of 3.65 microM against proliferation of MCF-7 cells, while 5n was the most potent with an IC(50) value of 5.09 microM against proliferation of A549 cells. Cell cycle analysis showed that both 5i and 5k arrested A549 cells at S and G2/M phases, suggesting that these compounds act through mechanisms different from 5-fluorouracil, which arrests cells at S phase only.

[Folate receptor-mediated antitumor drugs].

Folate receptor (FR) is over-expressed in a variety of human cancers and it is seldom expressed or found in normal tissues. Therefore, folate receptor-mediated antitumor drugs can be targeted specially to the FR-positive tumor cells. This strategy improves the selectivity of drugs which may destroy the normal tissues in traditional chemotherapeutics. This review provides the delivery mechanism of FR-mediated antitumor drugs and highlights the novel folate-drug conjugates and their activities.

Synthesis and cytotoxicity screening of piperazine-1-carbodithioate derivatives of 2-substituted quinazolin-4(3H)-ones.

A new series of piperazine-1-carbodithioate derivatives of 2-substituted quinazolin-4(3H)-ones were synthesized via a five-steps procedure starting from 2-amino-5-methylbenzoic acid. The cytotoxicity of the resulting compounds against A-549 (human lung cancer), HCT-8 (human colon cancer), HepG2 (human liver cancer), and K562 (human myelogenous leukaemia) cell lines was determined by the MTT assay. Preliminary screening results of these compounds are reported.

[Synthesis and in vitro antitumor activity of 4(3H)-quinazolinone derivatives bearing dithiocarbamate chains].

A series of 4(3H)-quinazolinone derivatives bearing dithiocarbamate side chains have been synthesized through the reaction of 6-bromomethyl-2-methyl-4(3H)-quinazolinone with CS2 and various amines in the presence of anhydrous K3PO4, and their structures were confirmed with ESI-MS, H NMR, elemental analysis or HRMS. The target compounds 8a -8q were tested for their in vitro antitumor activity against human myelogenous leukaemia K562 and human Hela cell lines by means of colorimetric MTT assay. Among the tested compounds, 8q exhibited in vitro inhibitory activity against K562 and Hela cells with IC50 values of 0.5 and 12.0 micromol x L(-01), respectively. Therefore, compound 8q is worthy to be a lead compound for the design and synthesis of new antitumor agents.