A Potent Chemotherapeutic Strategy with Eg5 Inhibitor against Gemcitabine Resistant Bladder Cancer

Targeting ketone body metabolism in mitigating gemcitabine resistance

Chemotherapy is often combined with surgery for muscle invasive and nonmuscle invasive bladder cancer (BCa). However, 70% of the patients recur within 5 years. Metabolic reprogramming is an emerging hallmark in cancer chemoresistance. Here, we report a gemcitabine resistance mechanism that promotes cancer reprogramming via the metabolic enzyme OXCT1. This mitochondrial enzyme, responsible for the rate-limiting step in β-hydroxybutyrate (βHB) catabolism, was elevated in muscle invasive disease and in patients with chemoresistant BCa. Resistant orthotopic tumors presented an OXCT1-dependent rise in mitochondrial oxygen consumption rate, ATP, and nucleotide biosynthesis. In resistant BCa, knocking out OXCT1 restored gemcitabine sensitivity, and administering the nonmetabolizable βHB enantiomer (S-βHB) only partially restored gemcitabine sensitivity. Suggesting an extrametabolic role for OXCT1, multi-omics analysis of gemcitabine sensitive and resistant cells revealed an OXCT1-dependent signature with the transcriptional repressor OVOL1 as a master regulator of epithelial differentiation. The elevation of OVOL1 target genes was associated with its cytoplasmic translocation and poor prognosis in a cohort of patients with BCa who have been treated with chemotherapy. The KO of OXCT1 restored OVOL1 transcriptional repressive activity by its nuclear translocation. Orthotopic mouse models of BCa supported OXCT1 as a mediator of gemcitabine sensitivity through ketone metabolism and regulating cancer stem cell differentiation.

Albendazole inhibits colon cancer progression and therapy resistance by targeting ubiquitin ligase RNF20

BACKGROUND

The repurposing of FDA-approved drugs for anti-cancer therapies is appealing due to their established safety profiles and pharmacokinetic properties and can be quickly moved into clinical trials. Cancer progression and resistance to conventional chemotherapy remain the key hurdles in improving the clinical management of colon cancer patients and associated mortality.

METHODS

High-throughput screening (HTS) was performed using an annotated library of 1,600 FDA-approved drugs to identify drugs with strong anti-CRC properties. The candidate drug exhibiting most promising inhibitory effects in in-vitro studies was tested for its efficacy using in-vivo models of CRC progression and chemoresistance and patient derived organoids (PTDOs).

RESULTS

Albendazole, an anti-helminth drug, demonstrated the strongest inhibitory effects on the tumorigenic potentials of CRC cells, xenograft tumor growth and organoids from mice. Also, albendazole sensitized the chemoresistant CRC cells to 5-fluorouracil (5-FU) and oxaliplatin suggesting potential to treat chemoresistant CRC. Mechanistically, Albendazole treatment modulated the expression of RNF20, to promote apoptosis in CRC cells by delaying the G2/M phase and suppressing anti-apoptotic-Bcl2 family transcription.

CONCLUSIONS

Albendazole, an FDA approved drug, carries strong therapeutic potential to treat colon cancers which are aggressive and potentially resistant to conventional chemotherapeutic agents. Our findings also lay the groundwork for further clinical testing.

Comprehensive Landscape of RRM2 with Immune Infiltration in Pan-Cancer

Simple Summary

RRM2 is a crucial subunit of ribonucleotide reductase. In this article, we provided a comprehensive analysis of RRM2 with immune infiltration in pan-cancer. We focused on the hotspots of ferroptosis-related gene RRM2 and immunotherapy. Via bioinformatics analysis, multiple indicators suggested that RRM2 high expression may enhance immunotherapy sensitivity. For the first time, we systematically analyzed the role of RRM2 in pan-cancer. We provided the prospect of RRM2 and immunotherapy for pan-cancer. Additionally, we proved the expression pattern, clinical value, prognostic value and potential pathways of RRM2 with different platforms. In particular, we confirmed RRM2 expression and function in bladder cancer in our clinical samples and cell lines. Collectively, we found that RRM2 is a novel prognostic biomarker, and these findings may aid in an improved understanding of the role of RRM2 and its clinical application in human cancers.

Abstract

As a crucial subunit of ribonucleotide reductase, RRM2 plays a significant part in DNA synthesis. This study aimed to elucidate the comprehensive landscape of RRM2 in human cancers. With different bioinformatics platforms, we investigated the expression pattern, prognostic significance, mutational landscapes, gene interaction network, signaling pathways and immune infiltration of RRM2 in tumors. We found that RRM2 expression was predominantly up-expressed in tumor tissues in most tumors. Concurrently, RRM2 expression was significantly associated with worse prognosis and tumor stage across TCGA cancers. Moreover, RRM2 high levels were critically associated with the infiltration of natural killer T cells and immune scores. RRM2 was positively related to immune checkpoints, tumor mutation burden, microsatellite instability, neoantigen, and cytotoxic T lymphocyte in several cancers, predicting effective response to immunotherapy. Meanwhile, a strong co-expression of RRM2 with immune-related genes was observed. Additionally, multiple Cox regression analysis showed that RRM2 was an independent prognostic factor in bladder cancer (BLCA). Eventually, we verified that RRM2 was overexpressed in BLCA clinical samples and cell lines. Blocking RRM2 could suppress BLCA cells’ growth and proliferation while enhancing sensitivity to cisplatin. This study provided a new perspective for understanding RRM2 in cancers and new strategies for tumor immunotherapy.

A Multiomics Profiling Based on Online Database Revealed Prognostic Biomarkers of BLCA

Background

Bladder cancer (BLCA) is one of the most common urological malignancies globally, posing a severe threat to public health. In combination with protein-protein interaction (PPI) network analysis of proteomics, Gene Set Variation Analysis (GSVA) and “CancerSubtypes” package of R software for transcriptomics can help identify biomarkers related to BLCA prognosis. This will have significant implications for prevention and treatment.

Method

BLCA data were downloaded from The Cancer Genome Atlas (TCGA) database and GEO database (GSE13507). GSVA analysis converted the gene expression matrix to the gene set expression matrix. “CancerSubtypes” classified patients into three subtypes and established a prognostic model based on differentially expressed gene sets (DEGSs) among the three subtypes. For genes from prognosis-related DEGSs, functional and pathway enrichment analyses and PPI network analysis were carried out. The Human Protein Atlas (HPA) database was used for validation. Finally, the proportion of tumor-infiltrating immune cells (TIICs) was determined using the CIBERSORT algorithm.

Results

In total, 414 tumor samples and 19 adjacent-tumor samples were obtained from TCGA, with 145 samples belonging to subtype A, 126 samples belonging to subtype B, and 136 samples belonging to subtype C. Then, we identified 83 DEGSs and constituted a prognostic signature with two of them: “GSE1460_CD4_THYMOCYTE_VS_THYMIC_STROMAL_CELL_DN” and “MODULE_253.” Finally, five subnets of two PPI networks were established, and nine core proteins were obtained: CDH2, COL1A1, EIF2S2, PSMA3, NAA10, DNM1L, TUBA4A, KIF11, and KIF23. The HPA database confirmed the expression of the nine core proteins in BLCA tissues. Furthermore, EIF2S2, PSMA3, DNM1L, and TUBA4A could be novel BLCA prognostic biomarkers.

Conclusions

In this study, we discovered two gene sets linked to BLCA prognosis. PPI analysis confirmed the network's core proteins, and several newly discovered biomarkers of BLCA prognosis were identified.

Negative Modulation of the Angiogenic Cascade Induced by Allosteric Kinesin Eg5 Inhibitors in a Gastric Adenocarcinoma In Vitro Model

Eg5 is a kinesin essential in bipolar spindle formation, overexpressed in tumours, thus representing a new target in cancer therapy. We aimed at evaluating the anti-cancer activity of Eg5 thiadiazoline inhibitors 2 and 41 on gastric adenocarcinoma cells (AGS), focusing on the modulation of angiogenic signalling. Docking studies confirmed a similar interaction with Eg5 to that of the parent compound K858. Thiadiazolines were also tested in combination with Hesperidin (HSD). Cell cycle analysis reveals a reduction of G1 and S phase percentages when 41 is administered as well as HSD in combination with K858. Western blot reveals Eg5 inhibitors capability to reduce PI3K, p-AKT/Akt and p-Erk/Erk expressions; p-Akt/Akt ratio is even more decreased in HSD+2 sample than the p-Erk/Erk ratio in HSD+41 or K858. VEGF expression is reduced when HSD+2 and HSD+41 are administered with respect to compounds alone, after 72 h. ANGPT2 gene expression increases in cells treated with 41 and HSD+2 compared to K858. The wound-healing assay highlights a reduction in the cut in HSD+2 sample compared to 2 and HSD. Thus, Eg5 inhibitors appear to modulate angiogenic signalling by controlling VEGF activity even better if combined with HSD. Overall, Eg5 inhibitors can represent a promising starting point to develop innovative anti-cancer strategies.

Role of KSP inhibitors as anti-cancer therapeutics: an update

Regardless of the growing discovery of anticancer treatments, targeting cancer-specific pathways, cytotoxic therapy still maintained its abundant clinical significance based on the fact that tumours harbour a greater population of actively dividing cells than normal tissues. Conventional anti-mitotic agents or microtubule poisons acting on the major mitotic spindle protein tubulin have been effectively used in clinical settings for cancer chemotherapy over the last three decades. However, use of these drugs is associated with limited clinical utility due to serious side effects such as debilitating and dose-limiting peripheral neuropathy, myelosuppression, drug resistance and allergic reactions. Therefore, research initiatives have been undertaken to develop novel microtubule motor proteins inhibitors that can potentially circumvent the limitations associated with conventional microtubule poisons. Kinesin spindle proteins (KSP) belonging to the kinesin-5 family play a crucial role during mitosis and unregulated cell proliferation. Several evidences from preclinical studies and different phases of clinical trials have presented kinesin spindle protein as a promising target for cancer therapeutics. kinesin spindle protein inhibitors causing mitosis disruption without interfering with microtubule dynamics in non-dividing cells offer a potential therapeutic alternative for the management of several major cancer types and are devoid of side effects associated with classical anti-mitotic drugs. This review summarizes recent data highlighting progress in the discovery of targeted KSP inhibitors and presents the development of scaffolds, structure-activity relationships, and outcomes of biological, and enzyme inhibition studies. We reviewed the recent literature reports published over last decade, using various electronic database searches such as PubMed, Embase, Medline, Web of Science, and Google Scholar. Clinical trial data till 2021 was retrieved from ClinicalTrial.gov. Major chemical classes developed as selective KSP inhibitors include dihydropyrimidines, β-carbolines, carbazoles, benzimidazoles, fused aryl derivatives, pyrimidines, fused pyrimidines, quinazolines, quinolones, thiadiazolines, spiropyran and azobenzenes. Drugs such as filanesib, litronesib, ispinesib have entered clinical trials, the most advanced phase explored being Phase II. KSP inhibitors have exhibited promising results; however, continued exploration is greatly required to establish the clinical potential of KSP inhibitors.

Mechanisms by Which Kinesin-5 Motors Perform Their Multiple Intracellular Functions

Bipolar kinesin-5 motor proteins perform multiple intracellular functions, mainly during mitotic cell division. Their specialized structural characteristics enable these motors to perform their essential functions by crosslinking and sliding apart antiparallel microtubules (MTs). In this review, we discuss the specialized structural features of kinesin-5 motors, and the mechanisms by which these features relate to kinesin-5 functions and motile properties. In addition, we discuss the multiple roles of the kinesin-5 motors in dividing as well as in non-dividing cells, and examine their roles in pathogenetic conditions. We describe the recently discovered bidirectional motility in fungi kinesin-5 motors, and discuss its possible physiological relevance. Finally, we also focus on the multiple mechanisms of regulation of these unique motor proteins.

KIF11 promotes cell proliferation via ERBB2/PI3K/AKT signaling pathway in gallbladder cancer

Proliferation is one of the significant hallmarks of gallbladder cancer, which is a relatively rare but fatal malignance. Aim of this study was to examine the biological impact and molecular mechanism of the candidate hub-gene on the proliferation and tumorigenesis of gallbladder cancer. We analyzed the differentially expressed genes and the correlation between these genes with MKI67, and showed that KIF11 is one of the major upregulated regulators of proliferation in gallbladder cancer (GBC). The Gene Ontology, Gene Sets Enrichment Analysis and KEGG Pathway analysis indicated that KIF11 may promote GBC cell proliferation through the ERBB2/PI3K/AKT signaling pathway. Gain-of-function and loss-of-function assay demonstrated that KIF11 regulated GBC cell cycle and cancer cell proliferation in vitro. GBC cells exhibited G2M phase cell cycle arrest, cell proliferation and clone formation ability reduction after treatment with Monastrol, a specific inhibitor of KIF11. Xenograft model showed that KIF11 promotes GBC growth in vivo. Rescue experiments showed that KIF11-induced GBC cell proliferation dependented on ERBB2/PI3K/AKT pathway. Moreover, we found that H3K27ac signals are enriched among the promoter region of KIF11 in the UCSC Genome Browser Database. Differentially expressed analysis showed that EP300, a major histone acetyltransferase modifying H3K27ac signal, is highly expressed in gallbladder cancer and correlation analysis illustrated that EP300 is positively related with KIF11 in almost all the cancer types. We further found that KIF11 was significantly downregulated in a dose-dependent and time-dependent manner after histone acetylation inhibitor treatment. The present results highlight that high KIF11 expression promotes GBC cell proliferation through the ERBB2/PI3K/AKT signaling pathway. The findings may help deepen our understanding of mechanism underlying GBC cancer development and development of novel diagnostic and therapeutic target.

Oblongifolin C reverses GEM resistance via suppressing autophagy flux in bladder cancer cells

A number of previous studies have demonstrated that inhibiting autophagy can increase the cellular cytotoxicity of chemotherapeutic agents in urothelial cancer cells. However, the mechanistic roles of autophagy in gemcitabine (GEM) resistant bladder cancer cells have not been thoroughly investigated. In the present study, immunohistochemistry staining of autophagy marker LC3 was performed in bladder cancer and healthy control tissues and demonstrated an essential role of autophagy in cancer development. A GEM-resistant cell line was established to assess the effects of autophagy on the acquisition of GEM resistance. Western blotting of autophagy markers in GEM-resistant bladder cancer cells suggested that GEM resistance was caused, at least partially, by GEM-induced autophagy. GEM resistance was demonstrated to be reversed by the inhibition of autophagy by 3-methyladenine. In addition, oblongifolin C (OC), a novel autophagic flux inhibitor purified from traditional Chinese medicine, was found to enhance the efficiency of GEM in GEM-resistant bladder cancer cells by inhibiting autophagic flux. In conclusion, data from the present study suggest that autophagy serves an important role in bladder cancer development and GEM resistance. OC treatment has the ability to reverse GEM-resistance in bladder cancer cells by suppressing autophagic flux, thereby providing a potential adjunctive therapeutic option for bladder cancer GEM treatment.

Inhibition of autophagy by chloroquine enhances the antitumor activity of gemcitabine for gallbladder cancer

Gemcitabine (GEM), as an anti-metabolic nucleoside analog, has been shown to have anticancer effects in various tumors, but its chemotherapy resistance is still an important factor leading to poor prognosis of cancer patient. A large number of studies in recent years have shown that autophagy plays an important role in the chemotherapy sensitivity of many tumors, including pancreatic, non-small cell lung, and bladder cancer. However, whether GEM causes autophagy in gallbladder cancer (GBC) and whether it is related to chemotherapy resistance is unknown. In the present study, we demonstrated that GEM induced apoptosis and protective autophagy in GBC cells, which may be related to the AKT/mTOR signaling pathway, and GEM in combination with autophagy inhibitor chloroquine can strengthen the cytotoxic effect of GEM on GBC in vitro and in vivo. These findings showed that both autophagy and AKT/mTOR signals were engaged in GBC cell death evoked by GEM, GBC patients might benefit from this new treatment strategy, and molecular targeted treatment in combination with autophagy inhibitors shows promise as a treatment improvement.

Design, synthesis, and molecular docking study of new monastrol analogues as kinesin spindle protein inhibitors

Lung, colorectal, and breast cancers are the top three types of cancer by incidence and are responsible for one-third of the cancer incidence and mortality. A series of 18 3,4-dihydropyrimidine analogues bearing a 1,2-methylenedioxybenzene component at position 4 with diverse side chains at positions 5 and 6 was designed and synthesized as inhibitors of the Eg5 kinesin enzyme. Target compounds were screened for their anticancer activity according to the NCI-USA protocol toward a panel of 60 cancer cell lines. Compounds 12a and 12b displayed the best antiproliferation activity against many cell lines. Interestingly, compound 12a displayed lethal effects against non-small-cell lung cancer NCI-H522 cells (-42.26%) and MDA-MB-468 breast cancer cells (-1.10%) at a single-dose assay concentration of 10^-5  M. Compounds 11c, 11d, 11g, 12a-d, 13, 15, and 18a were assayed against the kinesin enzyme, with IC₅₀ values ranging from 1.2 to 18.71 μM, which were more potent compared with monastrol (IC₅₀  = 20 μM). Cell cycle analysis of NCI-H522 cells treated with compound 12a showed cell cycle arrest at the G2/M phase. Furthermore, the expression levels of active caspase-3 and -9 were measured. A molecular docking study was performed for some demonstrative compounds as well as monastrol docked into the allosteric binding site of the kinesin spindle protein.

HSDL2 Promotes Bladder Cancer Growth In Vitro and In Vivo

Bladder cancer is a common malignant urinary tumor, and patients with bladder cancer have poor prognosis. Abnormal lipid metabolism in peroxisomes is involved in tumor progression. Hydroxysteroid dehydrogenase-like 2 (HSDL2) localized in peroxisomes regulates fatty acid synthesis. In the present study, we reported that HSDL2 was upregulated in two human bladder cancer cell lines 5637 and T24 compared to normal human urothelial cells. Furthermore, lentiviral-mediated HSDL2 knockdown inhibited the proliferation and colony formation while promoted the apoptosis of human bladder cancer T24 cells in vitro. In nude mice HSDL2 knockdown inhibited the growth of T24 derived xenografts in vivo. In conclusion, our results suggest that HSDL2 plays an oncogenic role in bladder cancer and might serve as a potential target for bladder cancer therapy.

Mitosis inhibitors in anticancer therapy: When blocking the exit becomes a solution

Current microtubule-targeting agents (MTAs) remain amongst the most important antimitotic drugs used against a broad range of malignancies. By perturbing spindle assembly, MTAs activate the spindle assembly checkpoint (SAC), which induces mitotic arrest and subsequent apoptosis. However, besides toxic side effects and resistance, mitotic slippage and failure in triggering apoptosis in various cancer cells are limiting factors of MTAs efficacy. Alternative strategies to target mitosis without affecting microtubules have, thus, led to the identification of small molecules, such as those that target spindle Kinesins, Aurora and Polo-like kinases. Unfortunately, these so-called second-generation of antimitotics, encompassing mitotic blockers and mitotic drivers, have failed in clinical trials. Our recent understanding regarding the mechanisms of cell death during a mitotic arrest pointed out apoptosis as the main variable, providing an opportunity to control the cell fates and influence the effectiveness of antimitotics. Here, we provide an overview on the second-generation of antimitotics, and discuss possible strategies that exploit SAC activity, mitotic slippage/exit and apoptosis induction, in order to improve the efficacy of anticancer strategies that target mitosis.

Gemcitabine and docetaxel as second-line chemotherapy in elderly patients with metastatic urothelial carcinoma: a retrospective analysis

Background

The objective of this study was to evaluate the efficacy of a combination of gemcitabine and docetaxel (GD) as a second-line treatment for elderly patients with metastatic urothelial carcinoma (mUC).

Patients and methods

A total of 122 patients with mUC who were previously treated with platinum-based chemotherapy received second-line GD therapy from July 2010 to June 2016. This consisted of 800 mg/m² gemcitabine and 40 mg/m² docetaxel on days 1 and 8 in each 21-day cycle. Using pooled cumulative data, we divided patients into the following three groups based on age: <65 years (Group A), from 65 to 74 years (Group B), and ≥75 years (Group C), and then the data were retrospectively analyzed. All patients were evaluated for treatment-related toxicities and assessed at every cycle by imaging studies. Kaplan-Meier curves were used for survival and recurrence analyses. Furthermore, potential prognostic factors for progression-free survival (PFS) and overall survival (OS) were assessed via univariate and multivariate Cox regression analyses.

Results

The median follow-up period was 8.2 months (range: 2.1-100). The median number of treatment cycles was three (range: 1-16) in Group A, three (1-15) in Group B, and two (1-11) in Group C. The objective response rate was not significantly different between the three groups. In addition, PFS and OS from the start of second-line GD therapy were also not significantly different. According to univariate and multivariate analyses of the second-line GD-treated cohort, a good performance status was the only prognostic factor for PFS and OS. In Group C, myelosuppression including predominant neutropenia and anemia, fatigue, and nausea were the main common adverse events. However, the incidence of neutropenia and a reduction in platelets were not significantly different between the three groups. Treatment-related deaths did not occur in this study.

Conclusion

In this study, GD combination therapy as a second-line treatment for mUC resulted in favorable tumor responses and few treatment-related toxicities, even among elderly patients.

Gemcitabine resistance mediated by ribonucleotide reductase M2 in lung squamous cell carcinoma is reversed by GW8510 through autophagy induction

Although chemotherapeutic regimen containing gemcitabine is the first-line therapy for advanced lung squamous cell carcinoma (LSCC), gemcitabine resistance remains an important clinical problem. Some studies suggest that overexpressions of ribonucleotide reductase (RNR) subunit M2 (RRM2) may be involved in gemcitabine resistance. We used a novel RRM2 inhibitor, GW8510, as a gemcitabine sensitization agent to investigate the therapeutic utility in reversing gemcitabine resistance in LSCC. Results showed that the expressions of RRM2 were increased in gemcitabine intrinsic resistant LSCC cells upon gemcitabine treatment. GW8510 not only suppressed LSCC cell survival, but also sensitized gemcitabine-resistant cells to gemcitabine through autophagy induction mediated by RRM2 down-regulation along with decrease in dNTP levels. The combination of GW8510 and gemcitabine produced a synergistic effect on killing LSCC cells. The synergism of the two agents was impeded by addition of autophagy inhibitors chloroquine (CQ) or bafilomycin A1 (Baf A1), or knockdown of the autophagy gene, Bcl-2-interacting protein 1 (BECN1). Moreover, GW8510-caused LSCC cell sensitization to gemcitabine through autophagy induction was parallel with impairment of DNA double-strand break (DSB) repair and marked increase in cell apoptosis, revealing a cross-talk between autophagy and DNA damage repair, and an interplay between autophagy and apoptosis. Finally, gemcitabine sensitization mediated by autophagy induction through GW8510-caused RRM2 down-regulation was demonstrated in vivo in gemcitabine-resistant LSCC tumor xenograft, further indicating that the sensitization is dependent on autophagy activation. In conclusion, GW8510 can reverse gemcitabine resistance in LSCC cells through RRM2 downregulation-mediated autophagy induction, and GW850 may be a promising therapeutic agent against LSCC as it combined with gemcitabine.

Effect of N-1 arylation of monastrol on kinesin Eg5 inhibition in glioma cell lines

An original and focused library of two sets of dihydropyrimidin-2-thiones (DHPMs) substituted with N-1 aryl groups derived from monastrol was designed and synthesized in order to discover a more effective Eg5 ligand than the template. Based on molecular docking studies, four ligands were selected to perform pharmacological investigations against two glioma cell lines. The results led to the discovery of two original compounds, called 20h and 20e, with an anti-proliferative effects, achieving IC50 values of about half that of the IC50 of monastrol in both cell lines. As with monastrol, flow cytometry analyses showed that the 20e and 20h compounds induced cell cycle arrest in the G2/M phase, and immunocytochemistry essays revealed the formation of monopolar spindles due to Eg5 inhibition without any toxicity to Caenorhabditis elegans.

S-trityl-L-cysteine, a novel Eg5 inhibitor, is a potent chemotherapeutic strategy in neuroblastoma

Eg5 is a member of the kinesin-5 family. It is involved in the formation of the bipolar spindle and serves a crucial role in mitosis; meaning that mitotic activation may serve as a chemotherapeutic strategy. However, the anticancer activity of Eg5 inhibitors in neuroblastoma remains uncharacterized. In the present study, the expression of Eg5 was examined in clinical tissue samples and neuroblastoma cell lines, SK-N-SH, SH-SY5Y and SK-N-BE2. Additionally, the antitumor activity of the Eg5 inhibitor, S-trityl-L-cysteine (STLC), was confirmed in vitro. STLC could mediate cell apoptosis, as well as cell cycle arrest, in a dose-dependent manner, which may contribute toward its antitumor activity. STLC-mediated apoptosis and cell cycle arrest were triggered by activation of the mitogen-activated protein kinase and nuclear factor kB signaling pathways. These results suggested that STLC may have potential in the in vivo treatment of neuroblastoma.

A pilot study of gemcitabine and paclitaxel as third-line chemotherapy in metastatic urothelial carcinoma

Background: We evaluated the effectiveness of gemcitabine and paclitaxel therapy in patients with metastatic urothelial carcinoma for whom two lines of sequential chemotherapy had been unsuccessful.

Methods: A total number of 105 patients who had previously received first-line chemotherapy consisting of gemcitabine and cisplatin or carboplatin, were treated with second-line gemcitabine and docetaxel therapy between June 2006 and May 2015. Of these patients, 15 with an Eastern Cooperative Oncology Group Performance Status of 0 or 1 were administered gemcitabine and paclitaxel as third-line treatment from 2013 after failure of the second-line therapy. For each 21-day cycle, gemcitabine (1000 mg/m²) was administered on days 1, 8, and 15, and paclitaxel (200 mg/m²) on day 1. Patients were assessed for each cycle and any adverse events were noted. Furthermore, a Short Form Health Survey questionnaire was used to assess each patient’s quality of life.

Results: Third-line gemcitabine and paclitaxel treatment cycles were undertaken for a median of four times (range 2–9). The disease control rate was 80.0%. After second-line gemcitabine and docetaxel therapy was completed, median progression-free survival and median overall survival were determined as 9.8 and 13.0 months, respectively. The only prognostic factor for overall survival, as determined by univariate and multivariate analyses, was third-line gemcitabine and paclitaxel therapy. Neutropenia (66.7%) and thrombocytopenia (53.3%) were noted as the grade 3 treatment-related toxicities. After two cycles of third-line gemcitabine and paclitaxel therapy, the pre- and post-treatment quality of life scores did not differ significantly.

Conclusions: Results demonstrate that third-line combination therapy using gemcitabine and paclitaxel is a feasible option for metastatic urothelial carcinoma patients.

Characterization of KIF11 as a novel prognostic biomarker and therapeutic target for oral cancer

Oral cancer has a high mortality rate, and its incidence is increasing gradually worldwide. As the effectiveness of standard treatments is still limited, the development of new therapeutic strategies is eagerly awaited. Kinesin family member 11 (KIF11) is a motor protein required for establishing a bipolar spindle in cell division. The role of KIF11 in oral cancer is unclear. Therefore, the present study aimed to assess the role of KIF11 in oral cancer and evaluate its role as a prognostic biomarker and therapeutic target for treating oral cancer. Immunohistochemical analysis demonstrated that KIF11 was expressed in 64 of 99 (64.6%) oral cancer tissues but not in healthy oral epithelia. Strong KIF11 expression was significantly associated with poor prognosis among oral cancer patients (P=0.034), and multivariate analysis confirmed its independent prognostic value. In addition, inhibition of KIF11 expression by transfection of siRNAs into oral cancer cells or treatment of cells with a KIF11 inhibitor significantly suppressed cell proliferation, probably through G2/M arrest and subsequent induction of apoptosis. These results suggest that KIF11 could be a potential prognostic biomarker and therapeutic target for oral cancer.

KIF11 is required for proliferation and self-renewal of docetaxel resistant triple negative breast cancer cells

Development of chemoresistance remains a major hurdle for triple negative breast cancer treatment. Previous studies suggest that CD44+/CD24- cells, subpopulation of cancer stem cells with self-renewing and tumor-initiating capacities, are partly responsible for chemoresistance and therapeutic failure of triple negative breast cancer. Therefore, novel agents that target cancer stem cells (CSCs) may improve the clinical outcome. KIF11 (kinesin family member 11), overexpressed in many cancer cells, is a molecular motor protein that plays essential role in mitosis. In this study, we assess its role in docetaxel resistant triple negative breast cancer (TNBC). We found that the expression of KIF11 was significantly increased in CD44+/CD24- subpopulation of docetaxel resistant TNBC cells. Knockdown of KIF11 resulted in a significant decrease in the percentage of CSCs and mammosphere formation. KIF11 knockdown also inhibits cell growth and induces cell cycle G2/M arrest followed by cell mitosis and apoptosis. Further docetaxel resistant TNBC xenograft models demonstrated that KIF11 inhibitor exerts growth inhibitory effect in vivo. Of note, we also found that KIF11 was highly expressed in TNBC and its expression was correlated with shorter disease free survival time. All these data indicate that KIF11 is critical for proliferation and self-renewal in TNBC tumor cells in vitro and in vivo, suggesting that KIF11 may be a promising therapeutic target for treating chemoresistant TNBC.

Role of 5-Aza-CdR in mitomycin-C chemosensitivity of T24 bladder cancer cells

Chemotherapeutic insensitivity is one of key obstacles to effectively treating muscle invasive bladder cancer. 5-Aza-2'-deoxycytidine (5-Aza-CdR) has been identified as a tumor suppressive agent in various types of cancer. The aim of the present study was to identify the effects of 5-Aza-CdR on the mitomycin-C (MMC) chemosensitivity of T24 bladder cancer cells and investigate the underlying mechanisms. T24 cells were treated with a combination of MMC and 5-Aza-CdR at various concentrations. The rates of proliferation and apoptosis were assessed by an MTT assay and flow cytometry, respectively. The expression of drug resistance-associated proteins, including P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1), and autophagy-associated proteins, including beclin 1, nucleoporin 62 (p62) and autophagy protein 5 (ATG5) were detected with western blotting. Treatment with 5-Aza-CdR significantly promoted the MMC chemosensitivity of T24 cells. The proliferation of T24 cells was significantly inhibited with increasing 5-Aza-CdR concentration, whereas apoptosis was significantly increased. This was associated with the decreased expression of P-gp, MRP1, beclin 1, p62 and ATG5. In conclusion, 5-Aza-CdR enhanced MMC chemosensitivity in bladder cancer T24 cells, which may be caused by the suppression of drug resistance- and autophagy-associated proteins.

Centromere protein U is a potential target for gene therapy of human bladder cancer

To investigate the role of centromere protein U (CENPU) in human bladder cancer (BCa), CENPU gene expression was evaluated in human BCa tissues. We used real-time quantitative PCR (qPCR) and found that CENPU gene expression in human BCa tissues was higher compared to that observed in cancer-adjacent normal tissues. High CENPU expression was found to be strongly correlated with tumor size and TNM stage. Kaplan-Meier survival analysis indicated that high CENPU levels were associated with reduced survival. We used a lentivirus to silence endogenous CENPU gene expression in the BCa T24 cell line. CENPU knockdown was confirmed by qPCR. Cellomic imaging and BrdU assays showed that cell proliferation was significantly reduced in the CENPU-silenced cells compared to that noted in the control cells. Flow cytometry revealed that in the CENPU-silenced cells the cell cycle was arrested at the G1 phase relative to that in the control cells. In addition, apoptosis was significantly increased in the CENPU-silenced cells. Giemsa staining showed that CENPU-silenced cells, compared to control cells, displayed a significantly lower number of cell colonies. The genome-wide effect of CENPU knockdown showed that a total of 1,274 differentially expressed genes was found, including 809 downregulated genes and 465 upregulated genes. Network analysis by Ingenuity Pathway Analysis (IPA) resulted in 25 distinct signaling pathways, including the top-ranked network: ‘Cellular compromise, organismal injury and abnormalities, skeletal and muscular disorders’. In-depth IPA analysis revealed that CENPU was associated with the HMGB1 signaling pathway. qPCR and western blot analysis demonstrated that in the HMGB1 signaling pathway, CENPU knockdown downregulated expression levels of ILB, CXCL8, RAC1 and IL1A. In conclusion, our data may provide a potential pathway signature for therapeutic targets with which to treat BCa.

CD52, CD22, CD26, EG5 and IGF-1R expression in thymic malignancies

BACKGROUND

Thymic epithelial tumours are rare cancers for which new treatment options are required. Identification of putative predictive markers is important for developing clinical trials. We studied the expression of five putative predictive biomarkers, potentially actionable by approved experimental drugs.

METHODS

CD52, CD22, CD26, EG5, and IGF-1R expression were investigated by immunohistochemistry in formalin-fixed surgical samples of thymic epithelial tumour patients. All samples containing 10% positive epithelial tumour cells, independent of tumour cell intensity, were considered as positive. Correlation with histological subtype was performed.

RESULTS

106 surgical samples (89 thymomas, 12 thymic carcinoma, and 5 thymic neuroendocrine tumours) were evaluated. Overall, CD52, CD22, CD26, EG5 and IGF-1R expression was observed in 7%, 42%, 25%, 42% and 77% of samples, respectively. CD52 expression was more frequent in B2 and B3 thymoma. All TET subtypes stained for CD22, mainly AB thymoma (68%). CD26 expression also correlated with AB thymoma (68%), and A thymoma (50%) subtype, while IGFR1 was the most common marker expressed by thymic carcinoma samples (92%), followed by EG5 (60%). Only EG5 expression was significantly higher in thymic carcinomas than in thymomas (75% vs. 38%, p=0.026).

CONCLUSIONS

Our data were consistent with a previous study of IGF-1R expression. Based on their expression, activity of agents targeting CD52, CD 22, CD26 and EG5 could be further explored in TET patients.

Comparison of the efficacy and feasibility of en bloc transurethral resection of bladder tumor versus conventional transurethral resection of bladder tumor: A meta-analysis

BACKGROUND

The aim of this meta-analysis was to compare the feasibility of en bloc transurethral resection of bladder tumor (ETURBT) versus conventional transurethral resection of bladder tumor (CTURBT).

METHODS

Relevant trials were identified in a literature search of MEDLINE, EMBASE, Cochrane Library, Web of Science, and Google Scholar using appropriate search terms. All comparative studies reporting participant demographics, tumor characteristics, study characteristics, and outcome data were included.

RESULTS

Seven trials with 886 participants were included, 438 underwent ETURBT and 448 underwent CTURBT. There was no significant difference in operation time between 2 groups (P = 0.38). The hospitalization time (HT) and catheterization time (CT) were shorter in ETURBT group (mean difference[MD] -1.22, 95% confidence interval [CI] -1.63 to -0.80, P < 0.01; MD -0.61, 95% CI -1.11 to -0.11, P < 0.01). There was significant difference in 24-month recurrence rate (24-month RR) (odds ratio [OR] 0.66, 95% CI 0.47-0.92, P = 0.02). The rate of complication with respect to bladder perforation (P = 0.004), bladder irritation (P < 0.01), and obturator nerve reflex (P < 0.01) was lower in ETURBT. The postoperative adjuvant intravesical chemotherapy was evaluated by subgroup analysis, and 24-month RR in CTURBT is higher than that in ETURBT in mitomycin intravesical irrigation group (P = 0.02).

CONCLUSION

The first meta-analysis indicates that ETURBT might prove to be preferable alternative to CTURBT management of nonmuscle invasive bladder carcinoma. ETURBT is associated with shorter HT and CT, less complication rate, and lower recurrence-free rate. Moreover, it can provide high-qualified specimen for the pathologic diagnosis. Well designed randomized controlled trials are needed to make results comparable.

Attenuative role of mangiferin in oxidative stress-mediated liver dysfunction in arsenic-intoxicated murines

Mangiferin (MAG), a natural xanthone mainly derived from mangoes, possesses great antioxidative potentials. The present study has been carried out to investigate the hepato-protective role of MAG, against arsenic (As)-induced oxidative damages in the murine liver. As, a well-known toxic metalloid, is ubiquitously found in nature and has been reported to affect nearly all the organs of the human body via oxidative impairment. Administration of As in the form of sodium arsenite (NaAsO2 ) at a dose of 10 mg/kg body weight for 3 months abruptly increased reactive oxygen species (ROS) level, led to oxidative stress and significantly depleted the first line of antioxidant defense system in the body. Moreover, As caused apoptosis in hepatocytes. Treatment with MAG at a dose of 40 mg/kg for body weight for 30 days simultaneously and separately after NaAsO2 administration decreased the ROS production and attenuated the alterations in the activities of all antioxidant indices. MAG also protected liver against the NaAsO2 -induced apoptosis and disintegrated hepatocytes, thus counteracting with As-induced toxicity. It could significantly inhibit the expression of different proapoptotic caspases and upregulate the expression of survival molecules such as Akt and Nrf2. On inhibiting Akt (by PI3K inhibitor, LY294002) and ERK1/2 (by ERK1/2 inhibitor, PD98059) specifically, caspase 3 got activated abolishing mangiferin's protective role on As-induced hepatotoxicity. So here, we have briefly elucidated the signaling cascades involved in As-induced apoptotic cell death in the liver and also the detailed cellular mechanism by which MAG provides protection to this organ. © 2016 BioFactors, 42(5):515-532, 2016.