Discovery of N-(4-((6-(3,5- Dimethoxyphenyl)-9H-purine derivatives as irreversible covalent FGFR inhibitors.

Fibroblast growth factor receptor (FGFR) is an attractive target for cancer therapy, but existing FGFR inhibitors appear to hardly meet the demand for clinical application. Herein, a number of irreversible covalent FGFR inhibitors were designed and synthesized by selecting several five- and six-membered azaheterocycles as parent scaffold with different substituents to take over the hydrophobic region in the active pocket of FGFR proteins. Among the resulting target compounds, III-30 showed the most potent effect on enzyme activity inhibition and anti-proliferative activity against the tested cancer cell lines. Significantly, III-30 could inhibit the enzyme activity by achieving irreversible covalent binding with FGFR1 and FGFR4 proteins. It could also regulate FGFR-mediated signaling pathway and mitochondrial apoptotic pathway to promote cancer cell apoptosis and inhibit cancer cell invasion and metastasis. Moreover, III-30 had a good metabolic stability and showed relatively potent anti-tumor activity in the MDA-MB-231 xenograft tumor mice model.

Regulatory loops between rice transcription factors OsNAC25 and OsNAC20/26 balance starch synthesis.

Several starch synthesis regulators have been identified, but these regulators are situated in the terminus of the regulatory network. Their upstream regulators and the complex regulatory network formed between these regulators remain largely unknown. A previous study demonstrated that NAM, ATAF, and CUC (NAC) transcription factors, OsNAC20 and OsNAC26 (OsNAC20/26), redundantly and positively regulate the accumulation of storage material in rice (Oryza sativa) endosperm. In this study, we detected OsNAC25 as an upstream regulator and interacting protein of OsNAC20/26. Both OsNAC25 mutation and OE resulted in a chalky seed phenotype, decreased starch content, and reduced expression of starch synthesis-related genes, but the mechanisms were different. In the osnac25 mutant, decreased expression of OsNAC20/26 resulted in reduced starch synthesis; however, in OsNAC25-overexpressing plants, the OsNAC25-OsNAC20/26 complex inhibited OsNAC20/26 binding to the promoter of starch synthesis-related genes. In addition, OsNAC20/26 positively regulated OsNAC25. Therefore, the mutual regulation between OsNAC25 and OsNAC20/26 forms a positive regulatory loop to stimulate the expression of starch synthesis-related genes and meet the great demand for starch accumulation in the grain filling stage. Simultaneously, a negative regulatory loop forms among the 3 proteins to avoid the excessive expression of starch synthesis-related genes. Collectively, our findings demonstrate that both promotion and inhibition mechanisms between OsNAC25 and OsNAC20/26 are essential for maintaining stable expression of starch synthesis-related genes and normal starch accumulation.

Multitargeting HDAC Inhibitors Containing a RAS/RAF Protein Interfering Unit.

In this work, a series of multitargeting histone deacetylase (HDAC) inhibitors capable of regulating the signal transduction between RAS protein and downstream effectors were obtained by introducing a zinc-ion-binding group into the framework of rigosertib via different linkers. Among them, two representative compounds, XSJ-7 and XSJ-10, not only showed stronger antiproliferative activity against many types of cancer cells including solid tumor cells but also presented more potent inhibition on different subtypes of HDAC than suberoylanilide hydroxamic acid (SAHA). Significantly, XSJ-10 presented moderate pharmacokinetic behaviors and showed stronger antitumor activity than oxaliplatin, SAHA, and rigosertib in the HT-29 xenograft mouse models without significant systemic toxicity. Research on the anticancer mechanism of XSJ-10 revealed that it can effectively induce the apoptosis of cancer cells and suppress the tumor by strongly inhibiting the RAS-RAF-MEK-ERK signaling pathway and the acetylation level of HDAC3.

Design, synthesis, and biological evaluation of a series of benzofuran[3,2-d]pyrimidine-4(3H)-one derivatives containing thiosemicarbazone analogs as novel PARP-1 inhibitors.

Poly ADP ribose polymerase-1 (PARP-1), one of the most important members of the PARP protein family, plays a crucial role in DNA damage repair, gene transcription, and apoptosis of cancer cells. In this work, benzofuran[3,2-d]pyrimidine-4(3H)-one was used as a framework to design and synthesize a series of novel PARP-1 inhibitors by introducing thiosemicarbazone or its derivatives into the scafford. Among all the target compounds, 19b and 19c were found to exhibit more potent inhibitory activity and higher selectivity against PARP-1 than Olaparib, especially the latter had an IC50 value of 0.026 µM against PARP-1 enzyme and a PARP-2/PARP-1 selectivity of 85.19-fold over Olapanib. Apart from strong cytotoxicity against the tested cancer cell lines, 19c was most sensitive to SK-OV-3 cells, with an IC50 value of 4.98 µM superior to Olaparib. Anti-cancer mechanism studies revealed that 19c could inhibit DNA single-strand breakage repair and aggravate DNA double-strand breakage by inhibiting PARP-1 activity, and promote the apoptosis of cancer cells through the mitochondrial apoptosis pathway.

Blockade of chemo-resistance to 5-FU by a CK2-targeted combination via attenuating AhR-TLS-promoted genomic instability in human colon cancer cells.

As highly expressed in several human cancers, Casein Kinase 2 (CK2) is involved in chemotherapy-induced resistance. As a new potent CK2 inhibitor, DN701 is used to overcome chemoresistance through its synergistic antitumor effect with 5-fluorouracil (5-FU). Translesion DNA synthesis (TLS) has drawn our attention because it is associated with the development of chemo-resistance and tumor recurrence. The in vitro biological properties of 5-FU-resistant colon cancer cells revealed that DN701 combined with 5-FU could overcome chemo-resistance via blocking CK2-mediated aryl hydrocarbon receptor (AhR) and TLS-induced DNA damage repair (DDR). Moreover, pharmacologic and genetic inhibitions of AhR potently reduced TLS-promoted genomic instability. The mechanistic studies showed that combined DN701 with 5-FU was investigated to inhibit CK2 expression level and AhR-TLS-REV1 pathway. Meanwhile, DN701 combined with 5-FU could reduce CK2-AhR-TLS genomic instability, thus leading to superior in vivo antitumor effect. The insights provide a rationale for combining DN701 with 5-FU as a therapeutic strategy for patients with colon cancer.

Design, synthesis and biological evaluation of phosphoroxy quinazoline derivatives as potential EGFRT790M/C797S inhibitors.

Owing to the urgency and importance of developing fourth-generation EGFR inhibitors that can effectively overcome C797S site mutation in NSCLC, Brigatinib was used in this work as a lead compound to modify its structure to obtain a series of phosphoroxy quinazoline derivatives. Biological study indicated that the inhibitory activity and selectivity of the target compounds on EGFRL858R/T790M/C797S/EGFRDel19/T790M/C797S enzymes and EGFRDel19/T790M/C797S overexpressed Ba/F3 cells were significantly better than those of Brigatinib. Among the target compounds, 8a exhibited the best biological activity in vitro. More importantly, 8a presented acceptable pharmacokinetic behaviors and showed potent anti-tumor efficacy in the Ba/F3-EGFRDel19/T790M/C797S subcutaneous xenograft mice model with the tumor growth inhibition value of 82.60% at a dose of 30 mg/kg. These results indicated that 8a, as a drug candidate of the novel fourth-generation EGFR small-molecule inhibitor, has high potentials to treat with NSCLC on EGFR with C797S mutation.

Circumventing drug resistance through a CK2-targeted combination via attenuating endogenous AhR-TLS-promoted genomic instability in human colorectal cancer cells.

As anchoring Casein Kinase 2 (CK2) in several human tumors, DN701 as a novel CK2 inhibitor was applied to reverse chemo-resistance via its antitumor effect synergized with oxaliplatin. Recently, translesion DNA synthesis (TLS) has attracted our attention for its association with chemo-resistance, as demonstrated by previous clinical data. The in vitro cell-based properties supported that oxaliplatin combined with DN701 could reverse drug resistance via blockading CK2-mediated aryl hydrocarbon receptor (AhR) and translesion DNA synthesis (TLS)-induced DNA damage repair. Moreover, pharmacologic or genetic inhibition on REV3L (Protein reversion less 3-like) greatly impaired TLS-induced genomic instability. Mechanistically, combination of oxaliplatin with DN701 was found to inhibit CK2 expression and AhR-TLS-REV3L axis signaling, implying the potential decrease of genomic instability. In addition, the combination of oxaliplatin with DN701 could reduce CK2-AhR-TLS-related genomic instability, leading to potent antitumor effects in vivo. Our study presents an underlying mechanism that DN701 could attenuate tumoral chemo-resistance via decaying CK2-mediated AhR and TLS genomic instability, suggesting a potential cancer chemotherapeutic modality to prolong survival in chemo-resistant patients.

A platinum(II) complex HY1-Pt overcomes cisplatin-induced resistance and attenuates metastasis of epithelial ovarian cancer by cancer cell stemness inhibition.

Tumor recurrence, acquired resistance and metastasis have severely limited the effect of clinical treatments for epithelial ovarian cancer. Recent researches reveal that cancer stem cells play important roles in the process of cisplatin-induced resistance and cancer cell metastasis. A platinum(II) complex (HY1-Pt) owning casein kinase 2 specificity reported in our recent research was herein applied to treat cisplatin-sensitive and cisplatin-resistant epithelial ovarian cancers, respectively, anticipating to achieve high anti-tumor efficacy. HY1-Pt showed highly efficient anti-tumor effect with low toxicity for either cisplatin-sensitive or cisplatin-resistant epithelial ovarian cancer both in vitro and in vivo. Biological studies indicated that HY1-Pt as a casein kinase 2 inhibitor could effectively overcome cisplatin resistance through the signaling pathway of Wnt/ß-catenin by inhibiting expression of the signature genes of cancer stemness cells in A2780/CDDP cells. Moreover, HY1-Pt could suppress tumor migration and invasion in vitro and in vivo, further proving that HY1-Pt can be a potent novel platinum(II) agent for cisplatin-resistant epithelial ovarian cancer treatment.

Platinum(IV) Prodrugs with Cancer Stem Cell Inhibitory Effects on Lung Cancer for Overcoming Drug Resistance.

Acquired resistance remains a major barrier for the treatment of non-small cell lung cancer, while cancer stem cells (CSCs) usually lead to the occurrence of drug resistance. We herein report a series of platinum(IV) prodrugs containing CSCs-inhibitory species derived from a known CSCs inhibitor BBI608 in the axial position. Among them, complex 15 exerted the most potent cytotoxicity against A549 and A549/CDDP cancer cells. Besides, 15 could suppress cancer cell stemness, superior to BBI608, and overcome cisplatin resistance. Following assays indicated that an enhanced intracellular accumulation of 15 effectively triggered DNA damage, induced ROS generation, activated mitochondrial apoptosis pathway, and suppressed cell motility via p53 pathway in A549/CDDP cells. In vivo tests indicated that 15 exhibited potent antitumor effects without causing loss in the body weight. Our study provides a novel and efficient approach to promote the antitumor activity of platinum-based prodrugs and overcome cisplatin resistance via inhibiting cancer cell stemness.

Design, synthesis and biological evaluation of antitumor platinum(II) agents conjugated with non-steroidal anti-inflammatory drug species.

As one of the key features of tumor, inflammation attracts much attention of many researchers for antitumor study, in which non-steroidal anti-inflammatory drugs (NSAIDs) have been widely investigated in anti-inflammatory treatments in cancers. Herein, we report a series of novel platinum(II) complexes derived from conjugation of several NSAIDs derivatives with two antitumor platinum(II) agents. The antitumor inhibitory effects of the synthesized compounds on a number of cancer cell lines were estimated. By taking the advantage of two bioactive moieties, these compounds exhibited stronger antitumor activity than their parent platinum agents, and some appeared to have capability of overcoming cisplatin resistance. Among them, IA-1 showed the best cytotoxicity and even exhibited stronger antitumor activity than cisplatin. Further research indicated that IA-1 induced significant DNA damage and ROS generation, accompanied by high cellular platinum accumulation, resulting in a much higher apoptosis rate than cisplatin in A2780 cells. Moreover, IA-1 was found to inhibit metastasis and invasion of A2780 cells by suppressing the COX-2/JAK2/STAT3 axis. All these results revealed that introduction of NSAIDs species efficiently sensitized cancer cells to the synthetic compounds, proving that NSAIDs can enhance the activity of the platinum(II) agents via inhibiting inflammation in cancer cells.

Discovery of phthalazino[1,2-b]-quinazolinone derivatives as multi-target HDAC inhibitors for the treatment of hepatocellular carcinoma via activating the p53 signal pathway.

In view of histone deacetylases (HDACs) as a promising target for cancer therapy, a series of phthalazino[1,2-b]-quinazolinone units were hybrided with ortho-aminoanilide or hydroxamic acid to serve as multi-target HDAC inhibitors for the treatment of solid tumors. Among the target compounds, 8h possessed nano-molar IC50 values toward the tested cancer cells and HDAC subtypes, which was more potent than the HDAC inhibitor SAHA (vorinostat). Mechanism study revealed that compound 8h could suppress the HepG2 cell proliferation via prompting the acetylation of histone 3 (H3) and α-tubulin, and activating the p53 signal pathway as designed. In addition, compound 8h exhibited much stronger in vivo antitumor efficacy than SAHA in the HepG2 xenograft tumor model with negligible toxicity. As a novel multi-target HDAC inhibitor, compound 8h deserves further development as a potential anticancer agent.

Conjugates Derived from Lapatinib Derivatives with Cancer Cell Stemness Inhibitors Effectively Reversed Drug Resistance in Triple-Negative Breast Cancer.

Increasing evidence indicates that the cancer stem cell (CSC) subpopulation contributes to the therapeutic resistance and metastasis of tumors, leading to patient recurrence and death. Herein, we designed and synthesized several compounds by conjugating lapatinib derivatives with different CSC inhibitors to treat with lapatinib-induced MDA-MB-231 drug-resistant cells. In vitro biological studies indicated that 3a showed strong cytotoxicity and EGFR enzyme inhibitory activity and effectively reversed lapatinib-mediated resistance of MDA-MB-231 cells via inhibiting triple-negative breast cancer (TNBC) cell stemness and the AKT/ERK signaling pathway. In addition, 3a was capable of strongly suppressing the invasion and migration of TNBC cells by inhibiting the Wnt/ß-catenin signaling pathway and MMP-2 and MMP-9 protein expression. In vivo tumorigenicity tests showed that 3a could inhibit the occurrence of TNBC by inhibiting BCSCs, proving 3a is a potential EGFR and CSC dual inhibitor for TNBC treatment.

Discovery of 5-(3-Chlorophenylamino)benzo[c][2,6]naphthyridine Derivatives as Highly Selective CK2 Inhibitors with Potent Cancer Cell Stemness Inhibition.

Multifunctional entities have recently been attractive for the development of anticancer chemotherapeutic drugs. However, such entities with concurrent CK2 along with cancer stem cell (CSC) inhibitory activities are rare in a single small molecule. Herein, a series of 5-(3-chlorophenylamino)benzo[c][2,6]naphthyridine derivatives were synthesized using a known CK2 inhibitor, silmitasertib (CX-4945), as the lead compound. Among the resulting compounds, 1c exhibited stronger CK2 inhibitory activity with higher Clk2/CK2 selectivity than CX-4945. Significantly, 1c could modulate the Akt1(ser129)-GSK-3ß(ser9)-Wnt/ß-catenin signaling pathway and inhibit the expression of the stemness marker ALDH1A1, CSC surface antigens, and stem genes, showing potent CSC inhibitory activity. Moreover, 1c also displayed superior pharmacokinetics and antitumor activity compared with CX-4945 sodium salt, without obvious toxicity. The favorable antiproliferative and antitumor activity of 1c, its high inhibitory selectivity for CK2, and its potent inhibition of cancer cell stemness make this molecule a candidate for the treatment of cancer.

Novel CK2-Specific Pt(II) Compound Reverses Cisplatin-Induced Resistance by Inhibiting Cancer Cell Stemness and Suppressing DNA Damage Repair in Non-small Cell Lung Cancer Treatments.

Cancer stem cells (CSCs) have a pivotal impact in drug resistance, tumor metastasis, and progression of various cancer entities, including in non-small cell lung cancer (NSCLC). A CK2 inhibitor HY1 was found to show potent CSC inhibitory effects in A549 cells. By taking advantage of inherent CK2 specificity and CSC inhibition of HY1, a Pt(II) agent (HY1-Pt) was developed by conjugation of HY1 with an active Pt(II) unit to reverse cisplatin-induced resistance in A549/cDDP cell treatment. In vitro biological studies indicated that HY1-Pt can target CK2, suppress DNA damage repair, reinforce cellular accumulation of platinum, and reverse resistance apart from effectively inhibiting CSCs through Wnt/ß-catenin signal pathway in A549/cDDP cells. Significantly, HY1-Pt presented an acceptable pharmacokinetic behavior and exhibited higher tumor growth inhibitory efficacy than cisplatin either in A549 or A549/cDDP xenograft models with low toxicity. Overall, HY1-Pt is a promising drug candidate for NSCLC treatment.

A trifunctional Pt(II) complex alleviates the NHEJ/HR-related DSBs repairs to evade cisplatin-resistance in NSCLC.

Cisplatin, a representative of platinum-based drug, is clinically and widely used in the treatment of various types of malignant cancer. However, its non-selectivity to almost all the cell lines and resistance in long-term use severely limit its scope of use. As biotin-specific uptake systems are overexpressed in many types of tumors but rarely occur in normal tissues, making biotin a promising target for cancer treatment. In the study, we synthesized the Pt(II) complex C2 and determined its biological activities. The existence of biotin enhanced the ability of the complex to target tumors, while the introduction of a naphthalimide compound makes it possible to diagnose tumors and monitor their progress. We have also introduced a known Pt(II) complex DN604, which not only retains the excellent cytotoxicity of platinum drugs, but also inhibits the expression of DNA double-strand breaks (DSBs) repair-related NHEJ protein Ku70 and HR protein Rad51. In summary, we report a novel trifunctional Pt(II) complex that could target tumor cells, monitor tumor progression, and reverse DSBs repair-induced cisplatin-resistance.

Systemic identification and analyses of genes potentially involved in chemosensory in the devastating tea pest Basilepta melanopus.

Basilepta melanopus is a serious insect pest of tea plantations in southern China. This tea pest poses a great threat to the tea industry in China. No effective and environmentally friendly methods have been established to control this pest at present. Olfactory genes play key roles in insect behaviour, and can potentially be used as targets for developing environmentally-friendly approaches for pest control. In this study, we produced a transcriptome derived from dissected antennae from B. melanopus using high-throughput sequencing. We identified gene families that are potentially involved in odorant reception and detection, including unigenes encoding 63 odorant receptors (ORs), 16 gustatory receptors (GRs), 18 ionotropic receptors (IRs), four sensory neuron membrane proteins (SNMPs), 46 odorant binding proteins (OBPs), and 19 chemosensory proteins (CSPs). Analyses of tissue expression profiles revealed that all 63 OR transcripts, 14 antennal IRs, one SNMP and six OBPs were predominately expressed in antennae. Real-time quantitative PCR assays were also adapted to examine sex-biased expression of selected antenna-predominant genes. Our results provide valuable information for further functional studies of olfactory genes in B. melanopus and potential novel targets for developing new pest control measures.

Carbon dots sensitized 2D-2D heterojunction of BiVO4/Bi3TaO7 for visible light photocatalytic removal towards the broad-spectrum antibiotics.

Focused on the removal of the complicated residual antibiotic in aqueous environment, in this work, a novel carbon dots (C-dots) sensitized 2D-2D heterojunction of BiVO4/Bi3TaO7 were assembled through a simple hydrothermal process. The characteristic by TEM, SEM, and XPS confirmed C-dots evenly anchored on the surface of BiVO4/Bi3TaO7 heterojunction. The as-prepared C-dots/BiVO4/Bi3TaO7 showed superior performance for the degradation of the various antibiotics under visible light illumination. When the concentration of C-dots in the composite is 3 wt.%, the photodegraded rates are obtained to be 91.7%, 89.3%, 87.1%, for tetracycline (TC), amoxicillin (AMX) and ciprofloxacin (CIP), respectively, without significant deactivation during consecutive ten recycle experiments. Furthermore, by assessing the antibiotics mixture solution of TC, AMX and CIP, it is proposed that the prepared samples are potentially effective for the wastewater effluents. A probable mechanism was reasonably proposed. The improved photocatalytic activities could be attributed to the unique construction of the C-dots mediated heterojunction, which could expedite electron migration, improve light harvesting capacity and enhance charge separation efficiency. The present investigation may provide a new perspective to design C-dots mediated heterojunction which could be a potential visible-light-driven photocatalysts for the better practical applications in remediation of broad-spectrum antibiotic residues.

Pt(IV) hybrids containing a TDO inhibitor serve as potential anticancer immunomodulators.

Tryptophan 2,3-dioxygenase (TDO), an immunosuppressive enzyme, can involve in immune evasion and tumor tolerance. TDO inhibitors can boost the efficacy of chemotherapeutics by promoting immunity. Herein, a strategy to introduce a TDO inhibitor into Pt(IV) complexes for reversing tumor immune suppression was adopted. A mono-modified Pt(IV) complex, 3, displayed significant antitumor activity against human liver cancer cells. Flow cytometry study revealed that complex 3 could induce cell death via a mitochondrial-dependent apoptosis pathway and arrest the cell cycle at S phase. Furthermore, complex 3 was effective to enhance T-cell immune responses by inhibiting the TDO enzyme expression to block the kynurenine production and inactivating the downstream of aryl hydrocarbon receptor (AHR).

[Adenovirus vector mediated human 14-3-3 γ gene transfer protects dopaminergic cells against rotenone-induced injury].

OBJECTIVE: To explore the protective effect of human 14-3-3 γ gene transfer on dopaminergic cells against rotenone-induced injury. METHODS: Adenovirus vector carrying the gene of 14-3-3 γ (Ad/14-3-3 γ) was employed to transfect PC12 cells. Then the cells were exposed to rotenone as a model of Parkinson's disease. Methyl thiazolyl tetrazolium (MTT) was used to assay the viability of PC12 cells. The 4',6-diamidino-2-phenylindole (DAPI) staining was used to analyze the apoptotic ratio of PC12 cells among the groups of control, Ad/14-3-3 γ, Ad-null and Rotenone. And high performance liquid chromatography (HPLC) was performed to detect the secreting functions of PC12 cells. The aggregates of α-Synuclein protein were detected under confocal microscopy. RESULTS: MTT showed that the cell absorbance A(570) of Ad/14-3-3 γ group (0.46 ± 0.09) was higher than that of Ad-null group (0.19 ± 0.08) and rotenone group (0.16 ± 0.07), but lower than that of normal control (0.63 ± 0.11), (all P < 0.01); HPLC-ECD showed that the levels of dopamine (189 ± 11) ng/ml and noradrenalin (55 ± 8) ng/ml in the culture fluid of Ad/14-3-3 γ group were higher than those of Ad-null group (79 ± 12, 38 ± 7) ng/ml and rotenone group (81 ± 13, 39 ± 7) ng/ml (all P < 0.01). DAPI staining showed that cell apoptosis ratio of group Ad/14-3-3 γ (27% ± 64%) was lower than that of group Ad-null (53% ± 10%) and rotenone group (56% ± 12%, P < 0.01), but higher than that of control group (10% ± 5%, P < 0.01). Under confocal microscopy, the aggregates of α-synuclein protein in PC12 cells were detected more in Ad-null group and rotenone group than that in Ad/14-3-3 γ group. CONCLUSION: Gene transfer of Ad/14-3-3 γ has a protective effect on dopaminergic cells against rotenone-induced injury.