Livin may serve as a marker for prognosis of bladder cancer relapse and a target of bladder cancer treatment

RNA-seq reveals novel mechanistic targets of Livin in bladder cancer

BACKGROUND

Bladder cancer is a very common malignancy with a high recurrence rate. The survival of patients with muscle-invasive bladder cancer is poor, and new therapies are needed. Livin has been reported to be upregulated in bladder cancer and influence the proliferation of cancer cells.

MATERIALS AND METHODS

The Livin gene in human bladder cancer cell line T24 was knocked out, and the differentially expressed genes were identified by RNA-seq and qPCR.

RESULTS

Livin knockdown affects gene expression and has strong negative effects on some cancer-promoting pathways. Furthermore, combined with bladder cancer clinical sample data downloaded from TCGA and GEO, 2 co-up-regulated genes and 58 co-down-regulated genes were identified and validated, which were associated with cancer proliferation and invasion.

CONCLUSION

All these results suggest that Livin plays an important role in bladder cancer and could be a potential anticancer target in clinical therapy.

Biologically responsive carrier-mediated anti-angiogenesis shRNA delivery for tumor treatment

Small interfering RNA (siRNA) has increased the hope for highly-efficient treatment of gene-related diseases. However, the stable and efficient delivery of therapeutic nucleic acids is a prerequisite for the successful clinical translation of RNA interfering therapy. To achieve this, we condensed the low molecular weight polyethyleneimine (PEI, Mw < 2000) with 2,6-pyridinedicarboxaldehyde (PDA) to synthesize a biologically responsive and degradable cationic polymer (abbreviated to PDAPEI) which was utilized as a gene vector for the delivery of a VEGF-A shRNA expression plasmid DNA (pDNA). The resulting electrostatic interaction between PDAPEI and pDNA led to the self-assembly of nanoscale polyplexes with suitable particle size and stable zeta potential. The PDAPEI/pDNA polyplexes demonstrated an outstanding gene transfection and silencing efficiency at 30 w/w ratio, as well as negligible cytotoxicity. Also, the designed polymer showed no stimulation to the innate immune system. Moreover, compared with PEI 25 KDa, the polyplexes accomplished comparatively better anti-angiogenesis efficacy, which resulted in the inhibition of tumor growth in subcutaneous tumor mice models. In conclusion, PDAPEI has great potential to be a gene delivery vector for cancer therapy.

Inhibition of livin expression suppresses cell proliferation and enhances chemosensitivity to cisplatin in human lung adenocarcinoma cells

Livin is a novel member of the inhibitor of apoptosis protein family that has been reported to be overexpressed in various types of human malignancy. Although several studies have demonstrated that livin may be used as an effective target for tumor therapy, few studies have investigated its role in human lung adenocarcinoma. In the present study, two different methods were used in order to investigate the tumor‑suppressing effect of livin in human lung adenocarcinoma cells. Firstly, small interfering (si)RNA technology was used to down regulate livin expression; siRNA-mediated knockdown of livin was confirmed using reverse transcription quantitative polymerase chain reaction and western blot analysis, and cell proliferations was assessed using an MTT assay in vitro. Secondly, inhibition of livin expression was induced through the synergistic inhibitory effect between flavopiridol and tumor necrosis factor‑related apoptosis-inducing ligand (TRAIL). Experimental results revealed that, following transfection of the livin gene-silencing vector, the gene expression of livin was markedly decreased, SPC-A1 cell proliferation was significantly reduced and the therapeutic effect of the chemotherapy drug cisplatin was markedly improved. This growth inhibitory effect was also observed in the flavopiridol and TRAIL combination treatment group. In the flavopiridol and TRAIL combination treatment group, the protein expression of livin was significantly reduced and the survival rate of SPC‑A1 cells was significantly lower than the flavopiridol and TRAIL single operation group. In conclusion, the RNA silencing and the synergistic inhibitory effect between flavopiridol with TRAIL was able to effectively inhibit the expression of livin, significantly decrease SPC-A1 tumor cell proliferation and significantly enhance sensitivity to the chemotherapy drug cisplatin. These findings suggest that livin may be used as a novel target for tumor gene therapy.

Targeted silencing of inhibitors of apoptosis proteins with siRNAs: a potential anti-cancer strategy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies, with a very poor prognosis. Despite significant improvements in diagnosis and treatment in recent years, the long-term therapeutic efficacy is poor, partially due to tumor metastasis, recurrence, and resistance to chemo- or radio-therapy. Recently, it was found that a major feature of tumors is a combination of unrestrained cell proliferation and impaired apoptosis. There are now 8 recognized members of the IAP-family: NAIP, c-IAP1, c-IAP2, XIAP, Survivin, Bruce, Livin and ILP-2. These proteins all contribute to inhibition of apoptosis, and provide new potential avenues of cancer treatment. As a powerful tool to suppress gene expression in mammalian cells, RNAi species for inhibiting IAP genes can be directed against cancers. This review will provide a brief introduction to recent developments of the application IAP-siRNA in tumor studies, with the aim of inspiring future treatment of HCC.

Expression of the apoptosis inhibitor livin in colorectal adenoma-carcinoma sequence: correlations with pathology and outcome

The inhibitor of apoptosis family member livin is expressed in several types of cancer but not in most benign tissues, and it has been considered to be a poor prognostic mark in various malignancies. However, livin expression and its prognostic relevance have not been evaluated in colorectal adenoma-carcinoma sequence. In this study, we analyzed the difference of livin expression among normal mucosa, adenoma, and adenocarcinoma and investigated the relationship of livin expression in carcinomas with clinicopathological variables using immunohistochemistry and real-time reverse transcription-PCR. We observed that the expression of livin protein was mainly present on base of colorectal crypts in adenoma and throughout the epithelium in carcinoma, whereas did not present in accompanying normal mucosa, and the expression of livin messenger RNA (mRNA) in adenocarcinomas was significantly higher than in adenomas and in normal mucosa (P = 0.001, respectively), whereas, compared with normal mucosa, the expression level of livin mRNA was up-regulated in adenomas but no significant difference (P = 0.196). We also found that the expression levels of livin mRNA in rectal cancer was significantly higher than those in colonic cancer, and livin mRNA expression was strongly related to colorectal cancer invasive depth but not to clinical tumor stage, differentiation, lymph node metastasis, tumor morphological category and pathological type, and patient's age and gender. These findings support the possibility that the livin gene may play a role in colorectal tumorigenesis, and increased expression of livin mRNA may serve as a new target for colorectal cancer treatment.

Knockdown of Livin inhibits growth and invasion of gastric cancer cells through blockade of the MAPK pathway in vitro and in vivo

Livin, a novel member of the human inhibitors of apoptosis protein family, has been shown to be critical for tumor progression and poor prognosis for several types of malignancies. However, limited reports exist regarding the biological functions of Livin in human gastric cancer (GC). The present study investigated the clinical significance of Livin and caspase-3 (CAS-3) in human GC using immunohistochemistry assay, and explore the potential using RNA interference to knockdown Livin expression, including the subsequent effects on tumor growth and invasion in GC cells in vitro and in vivo. Our results showed that the rate of positive expression of Livin was significantly higher in GC tissues compared to that in adjacent non-cancer tissues (ANCT) (64.1 vs. 30.8%, P<0.001), while CAS-3 was lower in GC tissues than in ANCT (33.3 vs. 66.7%, P=0.001). Livin expression was positively correlated with tumor differentiation and lymph node metastases (P=0.009; P=0.007), while CAS-3 was negatively correlated with them (P=0.036; P=0.002) in patients with GC. Furthermore, knockdown of Livin inhibited cell proliferative activities and invasive potential, and induced cell in situ apoptosis in GC cells, accompanied with decreased expression of p38 MAPK, VEGF and MMP-2 and increased expression of CAS-3. In addition, the tumor volumes in the SGC7901 subcutaneous nude mouse model treated with Lv-shLivin was significantly smaller compared to those of the PBS group (P<0.01). Taken together, our findings indicate that the expression of Livin is increased in human GC and correlates with tumor differentiation and lymph node metastases, while knockdown of Livin inhibits cell growth and invasion through blockade of the MAPK pathway in GC cells, suggesting that Livin may be a potential therapeutic target for the treatment of GC.

Tyroserleutide-based gene vector for suppressing VEGF expression in cancer therapy

A small interfering RNA (siRNA) plasmid DNA (pYr-1.1-hU6-EGFP-siVEGF) was constructed and used for suppressing vascular endothelial growth factor (VEGF) expression and inhibiting tumor growth. Then, a (tyrosyl-seryl-leucine)-polyethyleneimine-poly(ethylene glycol) (YSL-PEI-PEG) conjugate was designed and synthesized as a gene carrier for the delivery of pYr-1.1-hU6-EGFP-siVEGF plasmid. The therapeutic peptide YSL was conjugated to PEI to improve the anti-cancer efficiency, and the PEG chain was introduced to reduce the serum protein adsorption and improve the stability of the complex in the systemic circulation. It was found that YSL-PEI-PEG could efficiently condense plasmid DNA when the vector/DNA weight ratio was higher than 2. Compared with PEI 25 kDa, YSL-PEI-PEG exhibited higher transfection efficiency and lower cytotoxicity. More importantly, the results showed that the gene delivery system owned strong ability to inhibit cancer cell proliferation in vitro and tumor growth in vivo. YSL-PEI-PEG has great potential as a gene vector for clinical applications.

Oxymatrine induces human pancreatic cancer PANC-1 cells apoptosis via regulating expression of Bcl-2 and IAP families, and releasing of cytochrome c

BACKGROUND

Oxymatrine, an isolated extract from traditional Chinese herb Sophora Flavescens Ait, has been traditionally used for therapy of anti-hepatitis B virus, anti-inflammation and anti-anaphylaxis. The present study was to investigate the anti-cancer effect of oxymatrine on human pancreatic cancer PANC-1 cells, and its possible molecular mechanism.

METHODS

The effect of oxymatrine on the viability and apoptosis was examined by methyl thiazolyl tetrazolium and flow cytometry analysis. The expression of Bax, Bcl-2, Bcl-x (L/S), Bid, Bad, HIAP-1, HIAP-2, XIAP, NAIP, Livin and Survivin genes was accessed by RT-PCR. The levels of cytochrome c and caspase 3 protein were assessed by Western blotting.

RESULTS

Oxymatrine inhibited cell viability and induced apoptosis of PANC-1 cells in a time- and dose-dependent manner. This was accompanied by down-regulated expression of Livin and Survivin genes while the Bax/Bcl-2 ratio was upregulated. Furthermore, oxymatrine treatment led to the release of cytochrome c and activation of caspase-3 proteins.

CONCLUSION

Oxymatrine can induce apoptotic cell death of human pancreatic cancer, which might be attributed to the regulation of Bcl-2 and IAP families, release of mitochondrial cytochrome c and activation of caspase-3.

Expression of inhibitor of apoptosis protein Livin in gastric cancer and adjacent non-cancerous tissue

AIM: To detect the expression of Livin protein in gastric cancer and adjacent non-cancerous tissue, and to analyze its prognostic significance by exploring the relationship between Livin expression and the biological behavior of gastric cancer.

METHODS: The expression of Livin was detected by immunohistochemistry (streptavidin-peroxidase method) in 50 gastric cancer and matched adjacent non-cancerous tissue samples. Quantitative analysis of Livin expression was performed with the Image-Pro Plus 6.0 software. The significance of Livin expression in gastric cancer was then analyzed.

RESULTS: The integrated absorbance (IA) value of Livin staining in gastric cancer tissue was significantly higher than that in adjacent non-cancerous tissue (283 270.55 ± 199 604.16 vs 6 878.08 ± 9 214.56, P < 0.01). The IA value was lower in well and moderately differentiated cancer tissue than in poorly and undifferentiated tissue (41 288.94 ± 27 891.09 vs 359 690.5 ± 166 583.17, P < 0.01), in cancer tissue not invading the serosal layer than in that invading the serosal layer (T_3-4) (85 529.62 ± 115 287.42 vs 360 174.77 ± 170 507.09, P < 0.01), and in gastric cancer without lymph node metastasis than in that with lymph node metastasis (148 547.51 ± 152 479.47 vs 380 949.72 ± 171 073.92, P < 0.01).

CONCLUSION: Livin protein is highly expressed in gastric cancer. Livin expression is significantly associated with tumor differentiation, infiltration and lymph node metastasis in gastric caner. Livin protein may be used as a prognostic marker for gastric cancer.

Livin abrogates apoptosis of SPC-A1 cell by regulating JNKI signaling pathway

Livin, a novel member of inhibitors of apoptosis protein, is highly expressed in tumor tissues. It is a potential target in tumor therapy. Silencing its gene expression has been found to promote tumor cell apoptosis or increase tumor sensitivity to therapies. This paper studied the effect of livin anti-apoptotic activity and examined its molecular mechanisms. In the study, higher levels of cell apoptosis were measured by FACS in the experiment group with livin expression silenced than that in controls (P < 0.05). After livin gene expression was knocked down, cleaved caspase-3 protein was up-regulated but caspase-3 mRNA expression was almost the same, the phosphorylated JNK1 protein was down-regulated but JNK1 mRNA and total JNK1 protein expression was approximately the same too. The results suggest that livin may exert anti-apoptotic action on SPC-A1 by activating JNK1 signaling pathway and inhibiting caspase-3 activation.

Expression of Livin and vascular endothelial growth factor in different clinical stages of human esophageal carcinoma

AIM: To investigate the role of Livin and vascular endothelial growth factor (VEGF) in human esophageal carcinoma, and analyze its relationship to clinical stages.

METHODS: Expression of Livin in fresh esophageal cancer tissues was detected by immunohistochemistry (IHC), Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR), and VEGF by Western blotting and RT-PCR. All statistical analyses were performed by SPSS version 11.0.

RESULTS: Livin positivity was also significantly correlated with tumor stages, increasing with tumor progression. Expression of Livin and VEGF increased with the process of esophageal carcinoma. In the fourth clinical stage, expression of Livin and VEGF was the most significant. Expression of Livin was positively correlated with VEGF.

CONCLUSION: Over-expression of Livin and VEGF contributes to the pathogenesis of esophageal carcinoma.