Regorafenib combined with immune checkpoint inhibitors versus regorafenib monotherapy as a late-line treatment for metastatic colorectal cancer: a single-center, retrospective cohort study.

Background: Few data are available on metastatic colorectal cancer (mCRC) treated with late-line regorafenib monotherapy or combined with other therapies. This study thus aimed to examine regorafenib combined with immune checkpoint inhibitors (ICIs) compared with regorafenib monotherapy in patients with advanced CRC. Methods: This single-center retrospective cohort study included patients with advanced CRC who experienced recurrence and progression after standard first- and second-line treatments treatment from November 2018 to December 2021. The patients received regorafenib plus ICIs or regorafenib monotherapy. Treatment response was evaluated based on Response Evaluation Criteria in Solid Tumors (RECIST). Overall survival (OS) and progression-free survival (PFS) were analyzed via multivariate analysis. Results: The combined group and the monotherapy group included 30 and 43 patients, respectively. The median OS (13.7 vs. 10.1 months; P=0.10) and PFS (4 vs. 3.6 months; P=0.32) were not significantly different between the two groups. In males, the median OS was significantly longer in the combined group compared with the monotherapy group (not reached vs. 8.03 months; P=0.02), but the median PFS showed no significant difference (7.23 vs. 3.90 months; P=0.16). There was no significant difference in OS (P=0.71) or PFS (P=0.89) in females. Eastern Cooperative Oncology Group performance status (ECOG PS) 1 [vs. 0; hazard ratio (HR) =3.13, 95% confidence interval (CI): 1.61-6.10; P<0.001] was independently associated with PFS. ECOG PS 1 (vs. 0; HR =3.63, 95% CI: 1.54-8.56; P=0.003) and combined therapy (vs. monotherapy; HR =0.47, 95% CI: 0.22-0.99; P=0.048) were associated with OS. Conclusions: Regorafenib combined with ICIs led to numerically longer PFS and significantly prolonged OS in patients with mCRC compared to regorafenib monotherapy, especially in male patients.

Retrospective study of a novel hematological parameter for predicting the survival of patients with nasopharyngeal carcinoma.

Purpose: This study aims to explore the prognostic values of routine pre-treatment hematological parameters in patients with nasopharyngeal carcinoma (NPC). Methods: The hematological parameters and clinical data of patients with NPC were collected from January 2012 to December 2013 at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. The survival statistics were obtained by regularly following-up the patients. The cut-off values for the hematological parameters were calculated using X-tile software. SPSS version 24.0 was used for the statistical analysis. The relationship between the hematological parameters and the prognosis of patients with NPC was analyzed using the Kaplan-Meier method and Cox multivariate regression. The discriminating abilities of the factors, which predict the prognosis, were evaluated by utilizing the receiver operating characteristic (ROC) area under the curve (AUC). Results: This study included 179 patients with NPC. Multivariate analysis shows that pretreatment platelet-to-lymphocyte ratio (PLR; hazard ratio; HR = 0.44, 95% CI [0.21-0.91], p = 0.029), serum albumin (ALB; HR = 2.49, 95% CI [1.17-5.30], p = 0.018), and globulin (GLO; HR = 0.44, 95% CI [0.21-0.90], p = 0.024) are independent predictors for 5-year overall survival (OS) in patients with NPC. In addition, pre-treatment PLR (HR = 0.47, 95% CI [0.25-0.90], p = 0.022) and pre-treatment GLO (HR = 0.37, 95% CI [0.19-0.72], p = 0.001) are associated with 5-year progression-free survival (PFS) in patients with NPC. Based on the results of the multivariate analysis, we proposed a new biomarker GLO-PLR, which is observably correlated with the T stage, N stage and clinical stage in patients with NPC. The OS resolving ability of the GLO-PLR evaluated by AUC is 0.714, which is better than those of GLO and PLR. The PFS resolving ability of the GLO-PLR evaluated by AUC was 0.696, which is also better than those of GLO and PLR. Conclusion: Pre-treatment PLR, ALB, and GLO are independent predictors of 5-year OS in patients with NPC, where PLR and GLO are also independent predictors of 5-year FPS. Compared with other hematological parameters, the proposed GLO-PLR is an inexpensive, effective, objective, and easy-to-measure marker for predicting the prognosis of NPC.

Role of STING in the treatment of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a prevalent form of lung cancer. Patients with advanced NSCLC are currently being treated with various therapies, including traditional radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. However, a considerable proportion of advance patients who cannot benefit from them. Consequently, it is essential to identify a novel research target that offers an encouraging perspective. The stimulator of interferon genes (STING) has emerged as such a target. At present, it is confirmed that activating STING in NSCLC tumor cells can impede the proliferation and metastasis of dormant tumor cells. This review focuses on the role of STING in NSCLC treatment and the factors influencing its activation. Additionally, it explores the correlation between STING activation and diverse therapy modalities for NSCLC, such as radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. Furthermore, it proposes the prospect of innovative therapy methods involving nanoparticles, with the aim of using the features of STING to develop more strategies for NSCLC therapy.

Cuprotosis clusters predict prognosis and immunotherapy response in low-grade glioma.

Cuprotosis, an emerging mode of cell death, has recently caught the attention of researchers worldwide. However, its impact on low-grade glioma (LGG) patients has not been fully explored. To gain a deeper insight into the relationship between cuprotosis and LGG patients' prognosis, we conducted this study in which LGG patients were divided into two clusters based on the expression of 18 cuprotosis-related genes. We found that LGG patients in cluster A had better prognosis than those in cluster B. The two clusters also differed in terms of immune cell infiltration and biological functions. Moreover, we identified differentially expressed genes (DEGs) between the two clusters and developed a cuprotosis-related prognostic signature through the least absolute shrinkage and selection operator (LASSO) analysis in the TCGA training cohort. This signature divided LGG patients into high- and low-risk groups, with the high-risk group having significantly shorter overall survival (OS) time than the low-risk group. Its predictive reliability for prognosis in LGG patients was confirmed by the TCGA internal validation cohort, CGGA325 cohort and CGGA693 cohort. Additionally, a nomogram was used to predict the 1-, 3-, and 5-year OS rates of each patient. The analysis of immune checkpoints and tumor mutation burden (TMB) has revealed that individuals belonging to high-risk groups have a greater chance of benefiting from immunotherapy. Functional experiments confirmed that interfering with the signature gene TNFRSF11B inhibited LGG cell proliferation and migration. Overall, this study shed light on the importance of cuprotosis in LGG patient prognosis. The cuprotosis-related prognostic signature is a reliable predictor for patient outcomes and immunotherapeutic response and can help to develop new therapies for LGG.

Concurrent cisplatin or cetuximab with radiotherapy in patients with locally advanced head and neck squamous cell carcinoma: A meta-analysis.

BACKGROUND: Concurrent cisplatin with radiotherapy (CRT) or concurrent cetuximab with radiotherapy (BRT) improves outcomes in locally advanced head and neck squamous cell carcinoma (HNSCC) compared with radiotherapy alone. Nevertheless, a detailed comparison between CRT and BRT in locally advanced HNSCC is required due to inconclusive results. METHODS: A comprehensive literature search was conducted on PubMed, Web of Science, Cochrane databases, and EMBASE. Studies that evaluated CRT vs BRT in locally advanced HNSCC were included. The primary outcome that was overall survival (OS), whereas the secondary outcomes were progression-free survival (PFS), locoregional control (LRC), and distant metastasis-free survival (DMFS). Pooled hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) were used to evaluate prognosis. All the analyses were performed using Stata Statistical Software 12.0. RESULTS: Twenty-three studies, with a total of 8701 patients, were considered eligible and included in this meta-analysis. Our results revealed that patients treated with CRT had longer OS (HR = 0.51, 95%CI, 0.41-0.64, P < .001), PFS (HR = 0.37, 95%CI, 0.23-0.60, P < .001), LRC (HR = 0.46, 95%CI, 0.37-0.57, P < .001), and DMFS (HR = 0.56, 95%CI, 0.40-0.77, P < .001) than those treated with BRT. Furthermore, the results of the subgroup analyses were consistent with the primary analysis. CONCLUSIONS: CRT has a better OS, PFS, LRC, and DMFS than BRT in locally advanced HNSCC, and should be the preferred treatment for patients with the disease.

Identification of BTG1 Status in Solid Cancer for Future Researches Using a System Review and Meta-analysis.

Abundant studies have been conducted to identify how B-cell translocation gene 1 protein (BTG1) gene affects the differentiation, proliferation, metastasis of cancer cells, and how it further regulates the generation or development of diseases to influence the prognosis of patients. However, the data from single research were not powerful enough. The correlations between BTG1 expression and mechanisms of tumorigenesis or prognosis of patients are still in controversial. Our system review and meta-analysis provided a complete explanation about the association between BTG1 expression and clinicopathological features or prognosis of patients, which further laid a foundation for future research on BTG1. Fifteen eligible studies consisting of 1992 participants were included. We uncovered that BTG1 expression in solid tumors was associated with lymph node status (RR=0.66, 95% CI: 0.58-0.75, P=0.142), TMN stage status (RR=2.13, 95% CI: 1.71-2.65, P=0.001), T category (RR=1.90, 95% CI: 1.20-3.00, P=0.000), histological differentiation (RR=1.91, 95% CI: 1.55-2.37, P=0.012), vascular invasion (RR=0.90, 95% CI: 0.57-1.41, P=0.001). BTG1 low expression was significantly associated with overall survival (OS) (HR=0.47, 95% CI: 0.38-0.67, P=0.000). It concluded that BTG1 possessed the potential value for future research and could be recommended as a significant biomarker in solid tumor.

Pre-treatment Serum Lactate Dehydrogenase Predicts Distant Metastasis and Poor Survival in Nasopharyngeal Carcinoma.

Background: Pre-treatment serum lactate dehydrogenase (LDH) has emerged as prognostic factor for many cancers. In this study, we evaluated the value of LDH in predicting distant metastasis and poor survival for patients with nasopharyngeal carcinoma (NPC). Methods: Clinical data from 172 non-metastatic NPC patients were retrospectively collected and serum LDH levels were routinely measured before treatment. The independent-samples t test was used to calculate differences between serum LDH levels from the various patient groups. Receiver-operating characteristic (ROC) curve analysis was performed to select the optimal cutoff points. The Kaplan-Meier method and log-rank test were adopted to calculate and compare the distant metastasis free survival (DMFS) and overall survival (OS) rates. The Cox proportional hazards model was used to carry out univariate and multivariate analyses. Results: NPC patients progressed with distant metastasis often have higher pre-treatment serum LDH levels than those did not develop distant metastasis (mean LDH level was 237.1U/L and 108.8U/L, respectively, p=0.001). Elevated LDH level was identified as an independent prognostic factor for poor DMFS (hazard ratio (HR), 8.31; 95% confidence interval (CI), 2.44-28.32; p=0.001) and OS (HR, 4.45; 95% CI, 1.77-11.21; p=0.002). Moreover, subgroup analyses revealed significant associations between serum LDH level and worse survival in advanced stage patients. Conclusions: Pre-treatment serum LDH level can predict distant metastasis and associate with the poor survival in patients with NPC.

Identification of Potential Biomarkers in Glioblastoma through Bioinformatic Analysis and Evaluating Their Prognostic Value.

Glioblastoma is a common malignant tumor in the central nervous system with an extremely poor outcome; understanding the mechanisms of glioblastoma at the molecular level is essential for clinical treatment. In the present study, we used bioinformatics analysis to identify potential biomarkers associated with prognosis in glioblastoma and elucidate the underlying mechanisms. The result revealed that 552 common genes were differentially expressed between glioblastoma and normal tissues based on TCGA, GSE4290, and GSE 50161 datasets. Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and protein-protein interaction (PPI) network were carried out to gain insight into the actions of differentially expressed genes (DEGs). As a result, 20 genes (CALB1, CDC20, CDCA8, CDK1, CEP55, DLGAP5, KIF20A, KIF4A, NDC80, PBK, RRM2, SYN1, SYP, SYT1, TPX2, TTK, VEGFA, BDNF, GNG3, and TOP2A) were found as hub genes via CytoHubba in Cytoscape and functioned mainly by participating in cell cycle and p53 signaling pathway; among them, RRM2 and CEP55 were considered to have relationship with the prognosis of glioblastoma, especially RRM2. High expression of RRM2 was consistent with shorter overall survival time. In conclusion, our study displayed the bioinformatic analysis methods in screening potential oncogenes in glioblastoma and underlying mechanisms. What is more is that we successfully identified RRM2 as a novel biomarker linked with prognosis, which might be expected to be a promising target for the therapy of glioblastoma.

Effects of Dexamethasone in the Treatment of Recurrent Chronic Subdural Hematoma.

OBJECTIVE: Recurrent chronic subdural hematoma (CSDH) is not rare. Some studies have demonstrated the role of dexamethasone in the medical management of chronic subdural hematoma. However, no systematic study in the treatment of recurrent CSDH has been published. The aim of our study is to evaluate the efficacy and safety of dexamethasone in patients with recurrent CSDH. METHODS: We retrospectively reviewed medical records of consecutive patients from July 2010 to September 2014. A total of 27 patients with symptomatic recurrent CSDH were included in the analysis. Follow-up for each patient consisted of computed tomography or magnetic resonance imaging every 28 days from admission to the resolution of hematoma. Data were collected on hematoma volume, complications, and outcome. RESULTS: Among the 27 patients, 3 patients with recurrent CSDH were only treated by burr hole surgery. Of the other 24 patients who primarily underwent dexamethasone treatment, 17 (70.8%) patients were treated successfully with medical treatment, whereas 7 patients required reoperation. Complications were noted in 3 (12.5%) patients (1 hyperglycemia, 1 urinary tract infection, and 1 pneumonia). There was 1 mortality (4.2%) for massive brain infarction. Twenty-one of the 24 patients (87.5%) recovered to their previous functional levels. There was no statistical significance in Fisher text between surgery and dexamethasone regarding success, complication, and functional recovery rate. CONCLUSIONS: Patients with recurrent CSDH can be treated successfully and safely with the nonsurgical medical treatment of dexamethasone. By use of this method, reoperation may be avoided.

Overcoming chemo/radio-resistance of pancreatic cancer by inhibiting STAT3 signaling.

Chemo/radio-therapy resistance to the deadly pancreatic cancer is mainly due to the failure to kill pancreatic cancer stem cells (CSCs). Signal transducer and activator of transcription 3 (STAT3) is activated in pancreatic CSCs and, therefore, may be a valid target for overcoming therapeutic resistance. Here we investigated the potential of STAT3 inhibition in sensitizing pancreatic cancer to chemo/radio-therapy. We found that the levels of nuclear pSTAT3 in pancreatic cancer correlated with advanced tumor grade and poor patient outcome. Liposomal delivery of a STAT3 inhibitor FLLL32 (Lip-FLLL32) inhibited STAT3 phosphorylation and STAT3 target genes in pancreatic cancer cells and tumors. Consequently, Lip-FLLL32 suppressed pancreatic cancer cell growth, and exhibited synergetic effects with gemcitabine and radiation treatment in vitro and in vivo. Furthermore, Lip-FLLL32 reduced ALDH1-positive CSC population and modulated several potential stem cell markers. These results demonstrate that Lip-FLLL32 suppresses pancreatic tumor growth and sensitizes pancreatic cancer cells to radiotherapy through inhibition of CSCs in a STAT3-dependent manner. By targeting pancreatic CSCs, Lip-FLLL32 provides a novel strategy for pancreatic cancer therapy via overcoming radioresistance.

ATDC/TRIM29 phosphorylation by ATM/MAPKAP kinase 2 mediates radioresistance in pancreatic cancer cells.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by therapeutic resistance for which the basis is poorly understood. Here, we report that the DNA and p53-binding protein ATDC/TRIM29, which is highly expressed in PDAC, plays a critical role in DNA damage signaling and radioresistance in pancreatic cancer cells. Ataxia-telangiectasia group D-associated gene (ATDC) mediated resistance to ionizing radiation in vitro and in vivo in mouse xenograft assays. ATDC was phosphorylated directly by MAPKAP kinase 2 (MK2) at Ser550 in an ATM-dependent manner. Phosphorylation at Ser-550 by MK2 was required for the radioprotective function of ATDC. Our results identify a DNA repair pathway leading from MK2 and ATM to ATDC, suggesting its candidacy as a therapeutic target to radiosensitize PDAC and improve the efficacy of DNA-damaging treatment.

Antibody against CD44s inhibits pancreatic tumor initiation and postradiation recurrence in mice.

BACKGROUND & AIMS: CD44s is a surface marker of tumor-initiating cells (TICs); high tumor levels correlate with metastasis and recurrence, as well as poor outcomes for patients. Monoclonal antibodies against CD44s might eliminate TICs with minimal toxicity. This strategy is unclear for treatment of pancreatic cancer, and little is known about how anti-CD44s affect pancreatic cancer initiation or recurrence after radiotherapy. METHODS: One hundred ninety-two pairs of human pancreatic adenocarcinoma and adjacent nontumor pancreatic tissues were collected from patients undergoing surgery. We measured CD44s levels in tissue samples and pancreatic cancer cell lines by immunohistochemistry, real-time polymerase chain reaction, and immunoblot; levels were correlated with patient survival times. We studied the effects of anti-CD44s in mice with human pancreatic tumor xenografts and used flow cytometry to determine the effects on TICs. Changes in CD44s signaling were examined by real-time polymerase chain reaction, immunoblot, reporter assay, and in vitro tumorsphere formation assays. RESULTS: Levels of CD44s were significantly higher in pancreatic cancer than adjacent nontumor tissues. Patients whose tumors expressed high levels of CD44s had a median survival of 10 months compared with >43 months for those with low levels. Anti-CD44s reduced growth, metastasis, and postradiation recurrence of pancreatic xenograft tumors in mice. The antibody reduced the number of TICs in cultured pancreatic cancer cells and xenograft tumors, as well as their tumorigenicity. In cultured pancreatic cancer cell lines, anti-CD44s down-regulated the stem cell self-renewal genes Nanog, Sox-2, and Rex-1 and inhibited signal transducer and activator of transcription 3-mediated cell proliferation and survival signaling. CONCLUSIONS: The TIC marker CD44s is up-regulated in human pancreatic tumors and associated with patient survival time. CD44s is required for initiation, growth, metastasis, and postradiation recurrence of xenograft tumors in mice. Anti-CD44s eliminated bulk tumor cells as well as TICs from the tumors. Strategies to target CD44s cab be developed to block pancreatic tumor formation and post-radiotherapy recurrence in patients.

HAb18G/CD147 promotes pSTAT3-mediated pancreatic cancer development via CD44s.

PURPOSE: Signal transducer and activator of transcription 3 (STAT3) plays a critical role in initiation and progression of pancreatic cancer. However, therapeutically targeting STAT3 has failed clinically. We previously identified HAb18G/CD147 as an effective target for cancer treatment. In this study, we aimed to investigate the potential role of HAb18G/CD147 in STAT3-involved pancreatic tumorigenesis in vitro and in vivo. EXPERIMENTAL DESIGN: The expression of HAb18G/CD147, pSTAT3, and CD44s was determined in tissue microarrays. The tumorigenic function and molecular signaling mechanism of HAb18G/CD147 were assessed by in vitro cellular and clonogenic growth, reporter assay, immunoblot assay, immunofluorescence staining, immunoprecipitation, and in vivo tumor formation using loss or gain-of-function strategies. RESULTS: Highly expressed HAb18G/CD147 promoted cellular and clonogenic growth in vitro and tumorigenicity in vivo. Cyclophilin A (CyPA), a ligand of CD147, stimulated STAT3 phosphorylation and its downstream genes cyclin D1/survivin through HAb18G/CD147-dependent mechanisms. HAb18G/CD147 was associated and colocalized with cancer stem cell marker CD44s in lipid rafts. The inhibitors of STAT3 and survivin, as well as CD44s neutralizing antibodies suppressed the HAb18G/CD147-induced cell growth. High HAb18G/CD147 expression in pancreatic cancer was significantly correlated with the poor tumor differentiation, and the high coexpression of HAb18G/CD147-CD44s-STAT3 associated with poor survival of patients with pancreatic cancer. CONCLUSIONS: We identified HAb18G/CD147 as a novel upstream activator of STAT3, which interacts with CD44s and plays a critical role in the development of pancreatic cancer. The data suggest that HAb18G/CD147 could be a promising therapeutic target for highly aggressive pancreatic cancer and a surrogate marker in the STAT3-targeted molecular therapies.

Design, synthesis, and in vitro antitumor activity evaluation of novel 4-pyrrylamino quinazoline derivatives.

Here, we describe the design and synthesis of two series of 4-pyrrylamino quinazolines as new analogs of the epidermal growth factor receptor inhibitor gefitinib. In vitro antitumor activity of these novel compounds against pancreatic (Miapaca2) and prostate (DU145) cancer cell lines was evaluated. Compared with the parental gefitinib, all 18 derivatives show a greatly increased cytotoxicity to cancer cells. In vitro kinase inhibitory activity on epidermal growth factor receptor was also investigated. Among them, compounds GI-6, GII-4, GII-6, GII-8, and GII-9 are more potential receptor tyrosine kinase (RTK) inhibitors. Based on these results, we propose simple structure-activity relationship to provide information for designing and developing more potent antitumor agents.

Natural IAP inhibitor Embelin enhances therapeutic efficacy of ionizing radiation in prostate cancer.

Embelin is an active ingredient of traditional herbal medicine that exhibits anti-tumor effects in human prostate cancer cells. However, therapeutic effect of embelin in combination with conventional radiation therapy is not yet determined. In this study, we evaluate the sensitizing potential of embelin on ionizing radiation (IR) in a human prostate cancer model. In vitro, embelin combined with radiation potently suppressed prostate cancer PC-3 cell proliferation that was associated with S and G2/M arrest in cell cycle. Moreover, the combination treatment promoted caspase-independent apoptosis, as evidenced by the increased apoptotic cell death without caspase-3 activation, but not autophagy. Clonogenic survival assay showed that S-phase arrest was required for embelin-mediated radiosensitization. In vivo, embelin significantly improved tumor response to X-ray radiation in the PC-3 xenograft model. Combination therapy produced enhanced tumor growth delay and prolonged time to progression, with minimal systemic toxicity. Immunohistochemistry studies showed that embelin plus IR significantly inhibited cell proliferation, induced apoptosis, and decreased microvessel density in tumors as compared with either treatment alone, suggesting an enhanced combinatory inhibition on tumor suppression and angiogenesis. Our results demonstrate that embelin significantly facilitates tumor suppression by radiation therapy both in vitro and in vivo in the prostate cancer model. This finding warrants embelin as a novel adjuvant therapeutic candidate for the treatment of hormone-refractory prostate cancer that is resistant to radiation therapy.

Natural proteasome inhibitor celastrol suppresses androgen-independent prostate cancer progression by modulating apoptotic proteins and NF-kappaB.

BACKGROUND: Celastrol is a natural proteasome inhibitor that exhibits promising anti-tumor effects in human malignancies, especially the androgen-independent prostate cancer (AIPC) with constitutive NF-κB activation. Celastrol induces apoptosis by means of proteasome inhibition and suppresses prostate tumor growth. However, the detailed mechanism of action remains elusive. In the current study, we aim to test the hypothesis that celastrol suppresses AIPC progression via inhibiting the constitutive NF-κB activity as well as modulating the Bcl-2 family proteins. METHODOLOGY/PRINCIPAL FINDINGS: We examined the efficacy of celastrol both in vitro and in vivo, and evaluated the role of NF-κB in celastrol-mediated AIPC regression. We found that celastrol inhibited cell proliferation in all three AIPC cell lines (PC-3, DU145 and CL1), with IC50 in the range of 1-2 µM. Celastrol also suppressed cell migration and invasion. Celastrol significantly induced apoptosis as evidenced by increased sub-G1 population, caspase activation and PARP cleavage. Moreover, celastrol promoted cleavage of the anti-apoptotic protein Mcl-1 and activated the pro-apoptotic protein Noxa. In addition, celastrol rapidly blocked cytosolic IκBα degradation and nuclear translocation of RelA. Likewise, celastrol inhibited the expression of multiple NF-κB target genes that are involved in proliferation, invasion and anti-apoptosis. Celastrol suppressed AIPC tumor progression by inhibiting proliferation, increasing apoptosis and decreasing angiogenesis, in PC-3 xenograft model in nude mouse. Furthermore, increased cellular IκBα and inhibited expression of various NF-κB target genes were observed in tumor tissues. CONCLUSIONS/SIGNIFICANCE: Our data suggest that, via targeting the proteasome, celastrol suppresses proliferation, invasion and angiogenesis by inducing the apoptotic machinery and attenuating constitutive NF-κB activity in AIPC both in vitro and in vivo. Celastrol as an active ingredient of traditional herbal medicine could thus be developed as a new therapeutic agent for hormone-refractory prostate cancer.

Design and synthesis of novel Gefitinib analogues with improved anti-tumor activity.

There is an urgent need to design and develop new and more potent EGFR inhibitors with improved anti-tumor activity. Here we describe the design and synthesis of two series of 4-benzothienyl amino quinazolines as new analogues of the EGFR inhibitor Gefitinib. The anti-tumor activity of these novel Gefitinib analogues in 6 human cancer cell lines was examined. Compared with the parental Gefitinib, most of the new compounds show a markedly increased cytotoxicity to cancer cells. Furthermore, several of the series B compounds that side chains at position 7 contain either a methyl or ethyl group are potent pan-RTK inhibitors. Two representative compounds in this class, 15 and 17, have an enhanced capability to inhibit cancer cell growth and induce apoptosis in vitro and inhibit tumor formation in vivo in human cancer cells with high HER-2, as compared with the parental Gefitinib. Thus they may be promising lead compounds to be developed as an alternative for current Gefitinib therapy or for Gefitinb-resistant patients, potentially via simultaneously blocking multiple RTK signaling pathways.

A Smac-mimetic sensitizes prostate cancer cells to TRAIL-induced apoptosis via modulating both IAPs and NF-kappaB.

BACKGROUND: Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for human cancer therapy, prostate cancer still remains resistant to TRAIL. Both X-linked inhibitor of apoptosis (XIAP) and nuclear factor-kappaB function as key negative regulators of TRAIL signaling. In this study, we evaluated the effect of SH122, a small molecule mimetic of the second mitochondria-derived activator of caspases (Smac), on TRAIL-induced apoptosis in prostate cancer cells. METHODS: The potential of Smac-mimetics to bind XIAP or cIAP-1 was examined by pull-down assay. Cytotoxicity of TRAIL and/or Smac-mimetics was determined by a standard cell growth assay. Silencing of XIAP or cIAP-1 was achieved by transient transfection of short hairpin RNA. Apoptosis was detected by Annexin V-PI staining followed by flow cytometry and by Western Blot analysis of caspases, PARP and Bid. NF-kappaB activation was determined by subcellular fractionation, real time RT-PCR and reporter assay. RESULTS: SH122, but not its inactive analog, binds to XIAP and cIAP-1. SH122 significantly sensitized prostate cancer cells to TRAIL-mediated cell death. Moreover, SH122 enhanced TRAIL-induced apoptosis via both the death receptor and the mitochondrial pathway. Knockdown of both XIAP and cIAP-1 sensitized cellular response to TRAIL. XIAP-knockdown attenuated sensitivity of SH122 to TRAIL-induced cytotoxicity, confirming that XIAP is an important target for IAP-inhibitor-mediated TRAIL sensitization. SH122 also suppressed TRAIL-induced NF-kappaB activation by preventing cytosolic IkappaB-alpha degradation and RelA nuclear translocation, as well as by suppressing NF-kappaB target gene expression. CONCLUSION: These results demonstrate that SH122 sensitizes human prostate cancer cells to TRAIL-induced apoptosis by mimicking Smac and blocking both IAPs and NF-kappaB. Modulating IAPs may represent a promising approach to overcoming TRAIL-resistance in human prostate cancer with constitutively active NF-kappaB signaling.