Lenvatinib as second-line treatment in patients with unresectable hepatocellular carcinoma: A retrospective analysis.

Objective: The purpose of this study is to determine the efficacy and safety of lenvatinib as second-line therapy in Chinese patients with unresectable hepatocellular carcinoma (HCC). Methods: We performed a retrospective analysis of Chinese patients with unresectable HCC who received second-line treatment of lenvatinib at three institutions from November 2018 to February 2022. Demographic and clinicopathologic characteristics, data on the treatment regimens were obtained from medical records. Tumor response was evaluated every 4-6 weeks by modified Response Evaluation Criteria in Solid Tumors (mRECIST). Results: In total, 50 patients with unresectable HCC who received second-line treatment of lenvatinib were enrolled in this study. The objective response rate (ORR) was 18.0% and the disease control rate (DCR) was 74.0%, respectively. The duration of response (DoR) was 6.0 months. The median progression-free survival (PFS) and overall survival (OS) were 5.0 and 8.5 months, respectively. Patients who received ICIs combined with anti-angiogenic inhibitors as first-line therapy, achieving CR/PR at first-line therapy, with PFS≥6months at first-line therapy had a higher DCR. Univariate and multivariate analysis showed that AFP (ng/ml)<400, absence of extrahepatic metastasis, Child-Pugh A, tumor number<3, ICIs combined with anti-angiogenic inhibitors as first-line therapy, CR/PR to first-line therapy, and PFS≥6months at first-line therapy were independent factors of favorable PFS. Univariate analysis showed that absence of extrahepatic metastasis, tumor number<3, ICIs combined with anti-angiogenic inhibitors as first-line therapy, and PFS≥6months at first-line therapy were significantly associated with longer OS. Multivariate analysis showed that absence of extrahepatic metastasis, Child-Pugh A, tumor number<3, CR/PR to first-line therapy and PFS≥6months at first-line therapy were independent prognostic factors of OS. The majority of AEs were grade 1-2, and were reversible. Grade 3/4 AEs occurred in 12 patients (24.0%) and were mostly connected with hand-foot skin reactions (10.0%), and 10 patients had lenvatinib dose reductions. Two toxicity-related treatment interruptions were attributed to grade 3 hand-foot skin reaction, and grade 4 proteinuria, respectively. Conclusion: This study confirms the efficacy and safety of lenvatinib as second-line therapy after progression on sorafenib or ICIs combined with anti-angiogenic inhibitors.

Norcantharidin overcomes vemurafenib resistance in melanoma by inhibiting pentose phosphate pathway and lipogenesis via downregulating the mTOR pathway.

Melanoma is the most aggressive type of skin cancer with a high incidence and low survival rate. More than half of melanomas present the activating BRAF mutations, along which V600E mutant represents 70%-90%. Vemurafenib (Vem) is an FDA-approved small-molecule kinase inhibitor that selectively targets activated BRAF V600E and inhibits its activity. However, the majority of patients treated with Vem develop acquired resistance. Hence, this study aims to explore a new treatment strategy to overcome the Vem resistance. Here, we found that a potential anticancer drug norcantharidin (NCTD) displayed a more significant proliferation inhibitory effect against Vem-resistant melanoma cells (A375R) than the parental melanoma cells (A375), which promised to be a therapeutic agent against BRAF V600E-mutated and acquired Vem-resistant melanoma. The metabolomics analysis showed that NCTD could, especially reverse the upregulation of pentose phosphate pathway and lipogenesis resulting from the Vem resistance. In addition, the transcriptomic analysis showed a dramatical downregulation in genes related to lipid metabolism and mammalian target of the rapamycin (mTOR) signaling pathway in A375R cells, but not in A375 cells, upon NCTD treatment. Moreover, NCTD upregulated butyrophilin (BTN) family genes, which played important roles in modulating T-cell response. Consistently, we found that Vem resistance led to an obvious elevation of the p-mTOR expression, which could be remarkably reduced by NCTD treatment. Taken together, NCTD may serve as a promising therapeutic option to resolve the problem of Vem resistance and to improve patient outcomes by combining with immunomodulatory therapy.

Association between cigarette smoking and colorectal cancer sidedness: A multi-center big-data platform-based analysis.

BACKGROUND: Sidedness (right/left) of colorectal cancer (CRC) is essential for treatment. Whether carcinogenesis of tobacco varies by sidedness remains unclear. The present study aims to evaluate the sidedness tendency of cigarette smoking and to explore its impact on prognosis. METHODS: In the multi-center retrospective study, data on 46 166 Chinese CRC patients were extracted from a big-data platform. Logistic regression analyses were performed to evaluate qualitative and quantitative associations between smoking and tumor sidedness. Survival analyses were conducted in metastatic CRC. RESULTS: History of smoking was associated with left-sided CRC (LSCRC; Adjusted odds ratio, 1.25; 95% CI, 1.16 - 1.34; P < .001). The sidedness tendency towards LSCRC increased from non-smokers, to ex-smokers, and to current smokers (P for trend < .001). Longer duration (P for trend < .001) and larger total amount of cigarette smoking (P for trend < .001) were more associated with LSCRC, respectively. The association was confirmed in both left-sided colon cancer and rectal cancer, but was stronger for rectal cancer (P = .016). Alcoholism significantly enhanced the association by 7% (P = .027). Furthermore, prognostic advantage of metastatic LSCRC diminished among ever-smokers, with contrary survival impacts of smoking on either side of CRC. CONCLUSIONS: History of smoking was associated with LSCRC in a positive dose-response relationship, and presented opposite prognostic impacts on right- and left-sided tumors. Smoking potentially plays an instrumental role in the mechanism for sidedness heterogeneity in CRC.

An integrative pan-cancer analysis of biological and clinical impacts underlying ubiquitin-specific-processing proteases.

Ubiquitin-specific-processing proteases (USPs), the largest deubiquitinating enzyme (DUB) subfamily, play critical roles in cancer. However, clinical utility of USPs is hindered by limited knowledge about their varied and substrate-dependent actions. Here, we performed a comprehensive investigation on pan-cancer impacts of USPs by integrating multi-omics data and annotated data resources, especially a deubiquitination network. Meaningful insights into the roles of 54 USPs in 29 types of cancers were generated. Although rare mutations were observed, a majority of USPs exhibited significant expressional alterations, prognostic impacts and strong correlations with cancer hallmark pathways. Notably, from our DUB-substrate interaction prediction model, additional USP-substrate interactions (USIs) were recognized to complement knowledge gap about cancer-relevant USIs. Intriguingly, expression signatures of the USIs revealed clinically meaningful cancer subtypes, where key USPs and substrates cooperatively contributed to significant prognosis differences among subtypes. Overall, this investigation provides a valuable resource to assist mechanism research and clinical utility about USPs.

XPO1 inhibitor KPT-330 synergizes with Bcl-xL inhibitor to induce cancer cell apoptosis by perturbing rRNA processing and Mcl-1 protein synthesis.

XPO1 (exportin1) mediates nuclear export of proteins and RNAs and is frequently overexpressed in cancers. In this study, we show that the orally bioavailable XPO1 inhibitor KPT-330 reduced Mcl-1 protein level, by which it synergized with Bcl-xL inhibitor A-1331852 to induce apoptosis in cancer cells. KPT-330/A-1331852 combination disrupted bindings of Mcl-1 and Bcl-xL to Bax, Bak, and/or Bim, elicited mitochondrial outer membrane permeabilization, and triggered apoptosis. KPT-330 generally mitigated mRNA expression and protein synthesis rather than mRNA nuclear export or protein stability of Mcl-1. KPT-330 inhibited mTORC1/4E-BP1 and Mnk1/eIF4E axes, which disrupted the eIF4F translation initiation complex but was dispensable for Mcl-1 reduction and KPT-330/A-1331852 combination-induced apoptosis. Mature rRNAs are integral components of the ribosome that determines protein synthesis ability. KPT-330 impeded nucleolar rRNA processing and reduced total levels of multiple mature rRNAs. Reconstitution of XPO1 by expressing degradation-resistant C528S mutant retained rRNA amount, Mcl-1 expression, and Bcl-xL inhibitor resistance upon KPT-330 treatment. KPT-330/A-1331852 combination suppressed growth and enhanced apoptosis of non-small cell lung cancer xenografts. Therefore, we clarify the reason of apoptosis resistance of cancer cells to XPO1 inhibition and develop a potential strategy for treating solid tumors.

Targeting KPNB1 overcomes TRAIL resistance by regulating DR5, Mcl-1 and FLIP in glioblastoma cells.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine with potential anticancer effect, but innate and adaptive TRAIL resistance in majority of cancers limit its clinical application. Karyopherin ß1 (KPNB1) inhibition in cancer cells has been reported to abrogate the nuclear import of TRAIL receptor DR5 and facilitate its localization on the cell surface ready for TRAIL stimulation. However, our study reveals a more complicated mechanism. Genetic or pharmacological inhibition of KPNB1 potentiated TRAIL-induced apoptosis selectively in glioblastoma cells mainly by unfolded protein response (UPR). First, it augmented ATF4-mediated DR5 expression and promoted the assembly of death-inducing signaling complex (DISC). Second, it freed Bax and Bak from Mcl-1. Third, it downregulated FLIPL and FLIPS, inhibitors of caspase-8 cleavage, partly through upregulating ATF4-induced 4E-BP1 expression and disrupting the cap-dependent translation initiation. Meanwhile, KPNB1 inhibition-induced undesirable autophagy and accelerated cleaved caspase-8 clearance. Inhibition of autophagic flux maintained cleaved caspase-8 and aggravated apoptosis induced by KPNB1 inhibitor plus TRAIL, which were abolished by caspase-8 inhibitor. These results unveil new molecular mechanism for optimizing TRAIL-directed therapeutic efficacy against cancer.

Rg3 inhibits gemcitabine-induced lung cancer cell invasiveness through ROS-dependent, NF-κB- and HIF-1α-mediated downregulation of PTX3.

PTX3, a member of the long pentraxin subfamily, associated with innate immunity is indispensable for resistance to some cancer. Gemcitabine, an analog of cytosine arabinoside, has shown restrained benefits because of profound chemoresistance. The PTX3 expression on GEM in human lung cancer cells have not yet been clarified; the present study aimed to show reactive oxygen species (ROS) mediatory PTX3 expression through distinct mechanisms. Whereas ginsenoside Rg3 is a herbal medicine with strong antitumor activity. Furthermore, we tested the hypothesis; Rg3 abrogates GEM-induced production of ROS-mediated activation of Akt and extracellular signal-regulated kinase (ERK) pathways and inhibits nuclear piling-up of nuclear factor kappa B (NF-κB) and HIF-1α. On the basis of time and dose-dependent manner, our data demonstrated that GEM-induced PTX3 expression was dependent on ROS generation as it was abrogated by pretreatment of lung cancer cells with the free radical scavenger N-acetyl-l-cysteine. Our data demonstrated that PTX3 upregulation by GEM correlated with the time-dependent escalation of NF-κB and HIF-1α in the nucleus resulted from phosphorylation-induced degradation of IκBα, whereas HIF-1α upregulation was NF-κB-dependent. Increase in ROS expression in lung cancer cells on GEM treatment preceded the nuclear accumulation of NF-κB and HIF-1α and suppression of ROS diminished these effects. ERK1/2 and Akt activation mediated the effect of ROS on NF-κB and HIF-1α and their pharmacological inhibition suppressed GEM-induced PTX3. Our study findings reinforced the role regarding PTX3 signaling in GEM-induced resistance and pointed toward an unintended and undesired effect of chemotherapy and to get an active regimen; the synergy was associated with NF-κB downregulation in lung cancer.

KPNB1 inhibition disrupts proteostasis and triggers unfolded protein response-mediated apoptosis in glioblastoma cells.

The nuclear import receptor karyopherin ß1 (KPNB1) is involved in the nuclear import of most proteins and in the regulation of multiple mitotic events. Upregulation of KPNB1 has been observed in cancers including glioblastoma. Depletion of KPNB1 induces mitotic arrest and apoptosis in cancer cells, but the underlying mechanism is not clearly elucidated. Here, we found that downregulation and functional inhibition of KPNB1 in glioblastoma cells induced growth arrest and apoptosis without apparent mitotic arrest. KPNB1 inhibition upregulated Puma and Noxa and freed Mcl-1-sequestered Bax and Bak, leading to mitochondrial outer membrane permeabilization (MOMP) and apoptosis. Moreover, combination of Bcl-xL inhibitors and KPNB1 inhibition enhanced apoptosis in glioblastoma cells. KPNB1 inhibition promoted cytosolic retention of its cargo and impaired cellular proteostasis, resulting in elevated polyubiquitination, formation of aggresome-like-induced structure (ALIS), and unfolded protein response (UPR). Ubiquitination elevation and UPR activation in KPNB1-deficient cells were reversed by KPNB1 overexpression or inhibitors of protein synthesis but aggravated by inhibitors of autophagy-lysosome or proteasome, indicating that rebalance of cytosolic/nuclear protein distribution and alleviation of protein overload favor proteostasis and cell survival. Chronic activation of eIF2α/ATF4 cascade of UPR was responsible for the upregulation of Puma and Noxa, apoptosis and ABT-263 sensitivity. Taken together, our findings demonstrate that KPNB1 is required for proteostasis maintenance and its inhibition induces apoptosis in glioblastoma cells through UPR-mediated deregulation of Bcl-2 family members.

UMI-77 primes glioma cells for TRAIL-induced apoptosis by unsequestering Bim and Bak from Mcl-1.

Malignant glioma is the most common and aggressive form of brain tumor with poor prognosis of survival. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent but is insufficient of inducing apoptosis in some types of gliomas. In this study, we showed that the small-molecule Mcl-1 inhibitor UMI-77 sensitized glioma cells to TRAIL treatment, as evidenced by cell viability assay, Annexin V staining and JC-1 staining. Combination of UMI-77 and TRAIL in glioma cells led to the activation of caspase-8 and Bid, cleavage of caspase-3 and poly-ADP ribose polymerase (PARP), accumulation of tBid in the mitochondria and release of cytochrome c into the cytosol. UMI-77 alone or in combination with TRAIL untethered pro-apoptotic Bcl-2 proteins Bim and Bak from the sequestration of Mcl-1 and promoted the conformational activation of Bak. Small hairpin RNA (shRNA) of Bid attenuated the cleavage of caspase-8, Bid, caspase-3 and PARP, and reduced the cytotoxicity of UMI-77 plus TRAIL as compared with control shRNA cells, indicating this synergy entails the crosstalk between extrinsic and intrinsic apoptotic signaling. Taken together, UMI-77 enhances TRAIL-induced apoptosis by unsequestering Bim and Bak, which provides a novel therapeutic strategy for the treatment of gliomas.

Transdermal granisetron for the prevention of nausea and vomiting following moderately or highly emetogenic chemotherapy in Chinese patients: a randomized, double-blind, phase III study.

BACKGROUND: The granisetron transdermal delivery system (GTDS) has been demonstrated effectiveness in the control of chemotherapy-induced nausea and vomiting (CINV) in previous studies. This is the first phase III study to evaluate the efficacy and tolerability of GTDS in patients receiving moderately emetogenic chemotherapy (MEC) or highly emetogenic chemotherapy (HEC) in China. METHODS: A total of 313 patients were randomized into the GTDS group (one transdermal granisetron patch, 7 days) or the oral granisetron group (granisetron oral 2 mg/day, ≥2 days). The primary endpoint was the percentage of patients achieving complete control (CC) from chemotherapy initiation until 24 h after final administration (PEEP). Chi-square test and Fisher's exact test were used for statistical analysis. RESULTS: Two hundred eighty-one patients were included in the per protocol analysis. During PEEP, CC was achieved by 67 (47.52%) patients in the GTDS group and 83 (59.29%) patients in the oral granisetron group. There was no statistical significance between the groups (P=0.0559). However, the difference of the CC percentage mainly occurred on the first day of chemotherapy between the groups. The CC was 70.13% on day 1 in the GTDS group, which was significantly lower than that of 91.03% in the oral granisetron group in the full analysis set. In the following days of chemotherapy, the CC was similar between the groups. In terms of cisplatin-contained regimen and female, there was statistical significance between the groups. Both treatments were well tolerated and safe. The most common adverse event was constipation. CONCLUSIONS: GTDS provided effective and well-tolerated control of CINV in Chinese patients, especially to non-cisplatin-contained regimen.

Anti-cancer effects of 2-oxoquinoline derivatives on the HCT116 and LoVo human colon cancer cell lines.

The present study demonstrated the anti-tumor effects of the quinoline derivative [5-(3-chloro-oxo-4-phenyl-cyclobutyl)-quinoli-8-yl-oxy] acetic acid hydrazide (CQAH) against colorectal carcinoma. Substantial apoptotic effects of CQAH on HCT116 and LoVo human colon cancer cell lines were observed. Apoptosis was identified based on cell morphological characteristics, including cell shrinkage and chromatin condensation as well as Annexin V/propidium iodide double staining followed by flow cytometric analysis and detection of apoptosis-associated proteins by western blot analysis. CQAH induced caspase-3 and PARP cleavage, reduced the expression of the anti-apoptotic proteins myeloid cell leukemia-1 and B-cell lymphoma (Bcl) extra large protein and elevated the expression of the pro-apoptotic protein Bcl-2 homologous antagonist killer. In addition, pharmacological inhibition of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, significantly reduced CQAH-mediated cell death as well as cleavage of caspase-3 and PARP. Co-treatment of CQAH with the commercial chemotherapeutics 5-fluorouracil and camptothecin-11 significantly improved their efficacies. Comparison of the apoptotic effects of CQAH with those of two illustrated structure-activity associations for this compound type, indicating that substitution at position-4 of the azetidine phenyl ring is pivotal for inducing apoptosis. In conclusion, the results of the present study indicated CQAH and its analogues are potent candidate drugs for the treatment of colon carcinoma.

Ginsenoside Rg3 suppresses FUT4 expression through inhibiting NF-κB/p65 signaling pathway to promote melanoma cell death.

Abnormal glycosylation is catalyzed by the specific glycosyltransferases and correlates with tumor cell apoptosis. Increased fucosyltransferase IV (FUT4) is seen in many types of cancer, and manipulating FUT4 expression through specific signaling pathway inhibits cell growth and induces apoptosis. NF-κB is known playing a vital role to control cell growth and apoptosis. Ginsenoside Rg3 is an herbal medicine with strong antitumor activity through inhibiting tumor growth and promoting tumor cell death. However, whether Rg3-induced inhibition on tumor development involves reduced NF-κB signaling and FUT4 expression remains unknown. In the present study, we found that Rg3 suppressed FUT4 expression by abrogating the binding of NF-κB to FUT4 promoter through inhibiting the expression of signaling molecules of NF-κB pathway, reducing NF-κB DNA binding activity and NF-κB transcription activity. NF-κB inhibitor (Bay 11-7082) or knocking down p65 expression by p65 siRNA also led to a significant decreased FUT4 expression. In addition, Rg3 induced apoptosis by activating both extrinsic and intrinsic apoptotic pathways. Moreover, in a xenograft mouse model, Rg3 downregulated FUT4 and NF-κB/p65 expression and suppressed melanoma cell growth and induced apoptosis without any noticeable toxicity. In conclusion, Rg3 induces tumor cell apoptosis correlated with its inhibitory effect on NF-κB signaling pathway-mediated FUT4 expression. Results suggest Rg3 might be a novel therapy agent for melanoma treatment.

Effects of cinobufacini injection on cell proliferation and the expression of topoisomerases in human HepG-2 hepatocellular carcinoma cells.

The present study aimed to investigate the effects of cinobufacini injection on the proliferation and expression of topoisomerases in human HepG-2 hepatocarcinoma cells. The cells were divided into a control group and an experimental group, in which 0.105, 0.21, 0.42 mg/l cinobufacini was injected. Cell proliferation was assessed using a 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide assay, levels of apoptosis were detected using annexin V/propidium iodide staining and cell cycles were analyzed using flow cytometric analysis. The mRNA and protein expression levels of topoisomerase (TOPO) I and TOPO II were determined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. Cinobufacini injection significantly inhibited the proliferation of the HepG-2 cells (P<0.05), induced apoptosis (P<0.05) in a dose- and time-dependent manner, induced tumor cell arrest at the S phase in a dose-dependent manner, and downregulated the mRNA and protein expression levels of TOPO I and TOPO II (P<0.05) in a dose-dependent manner. Therefore, cinobufacini was found to inhibit human HepG-2 hepatocellular carcinoma cell proliferation, and downregulation of the expression levels of TOPO I and TOPO II may contribute to the effect on proliferation observed in the Hep­G2 cells following cinobbufacini injection.

Ginsenoside Rg3-induced EGFR/MAPK pathway deactivation inhibits melanoma cell proliferation by decreasing FUT4/LeY expression.

Malignant melanoma is a destructive and lethal form of skin cancer with poor prognosis. An effective treatment for melanoma is greatly needed. Ginsenoside Rg3 is a herbal medicine with high antitumor activity. It is reported that abnormal glycosylation is correlated with the tumor cell growth. However, the antitumor effect of Rg3 on melanoma and its mechanism on regulating glycosylation are unknown. We found that Rg3 did not only inhibit A375 melanoma cell proliferation in a dose-dependent manner, but also decreased the expression of fucosyltransferase IV (FUT4) and its synthetic product Lewis Y (LeY), a tumor-associated carbohydrate antigen (TACA). Knocking down FUT4 expression by siRNA dramatically reduced FUT4/LeY level and inhibited cell proliferation through preventing the activation of EGFR/MAPK pathway. Consistently, the inhibitory effect of the Rg3 and FUT4 knockdown on melanoma growth was also seen in a xenograft melanoma mouse model. In conclusion, Rg3 effectively inhibited melanoma cell growth by downregulating FUT4 both in vitro and in vivo. Targeting FUT4/LeY mediated fucosylation by Rg3 inhibited the activation of EGFR/MAPK pathway and prevented melanoma growth. Results from this study suggest Rg3 is a potential novel therapy agent for melanoma treatment.

Ginsenoside Rg3 inhibits melanoma cell proliferation through down-regulation of histone deacetylase 3 (HDAC3) and increase of p53 acetylation.

Malignant melanoma is an aggressive and deadly form of skin cancer, and despite recent advances in available therapies, is still lacking in completely effective treatments. Rg3, a monomer extracted from ginseng roots, has been attempted for the treatment of many cancers. It is reported that the expressions of histone deacetylase 3 (HDAC3) and p53 acetylation correlate with tumor cell growth. However, the antitumor effect of Rg3 on melanoma and the mechanism by which it regulates HDAC3 expression and p53 acetylation remain unknown. We found high expression of HDAC3 in human melanoma tissues to be significantly correlated to lymph node metastasis and clinical stage of disease (p<0.05). In melanoma cells, Rg3 inhibited cell proliferation and induced G0/G1 cell cycle arrest. Rg3 also decreased the expression of HDAC3 and increased the acetylation of p53 on lysine (k373/k382). Moreover, suppression of HDAC3 by either siRNA or a potent HDAC3 inhibitor (MS-275) inhibited cell proliferation, increased p53 acetylation and transcription activity. In A375 melanoma xenograft studies, we demonstrated that Rg3 and HDAC3 short hairpin RNA (shHDAC3) inhibited the growth of xenograft tumors with down-regulation of HDAC3 expression and up-regulation of p53 acetylation. In conclusion, Rg3 has antiproliferative activity against melanoma by decreasing HDAC3 and increasing acetylation of p53 both in vitro and in vivo. Thus, Rg3 serves as a potential therapeutic agent for the treatment of melanoma.

A three-dimensional cadmium(II) coordination polymer: poly[[[µ-4,4'-(propane-1,3-diyl)dipyridine-κ(2)N:N](µ-3,3'-thiodipropionato-κ(3)O,O':O)cadmium(II)] monohydrate].

In the title coordination polymer, {[Cd(C6H8O4S)(C13H14N2)]·H2O}n, the Cd(II) atom displays a distorted octahedral coordination, formed by three carboxylate O atoms and one S atom from three different 3,3'-thiodipropionate ligands, and two N atoms from two different 4,4'-(propane-1,3-diyl)dipyridine ligands. The Cd(II) centres are bridged through carboxylate O atoms of 3,3'-thiodipropionate ligands and through N atoms of 4,4'-(propane-1,3-diyl)dipyridine ligands to form two different one-dimensional chains, which intersect to form a two-dimensional layer. These two-dimensional layers are linked by S atoms of 3,3'-thiodipropionate ligands from adjacent layers to form a three-dimensional network.

A novel small molecule aurora kinase inhibitor attenuates breast tumor-initiating cells and overcomes drug resistance.

Chemoresistance is a major cause of cancer treatment failure. Tumor-initiating cells (TIC) have attracted a considerable amount of attention due to their role in chemoresistance and tumor recurrence. Here, we evaluated the small molecule Aurora kinase inhibitor AKI603 as a novel agent against TICs in breast cancer. AKI603 significantly inhibited Aurora-A (AurA) kinase and induced cell-cycle arrest. In addition, the intragastric administration of AKI603 reduced xenograft tumor growth. Interestingly, we found that breast cancer cells that were resistant to epirubicin expressed a high level of activated AurA and also have a high CD24(Low)/CD44(High) TIC population. The inhibition of AurA kinase by AKI603 abolished the epirubicin-induced enrichment of TICs. Moreover, AKI603 suppressed the capacity of cells to form mammosphere and also suppressed the expression of self-renewal genes (ß-catenin, c-Myc, Sox2, and Oct4). Thus, our work suggests the potential clinical use of the small molecule Aurora kinase inhibitor AKI603 to overcome drug resistance induced by conventional chemotherapeutics in breast cancer.