Potent antitumor activity of oncolytic adenovirus expressing mda-7/IL-24 for colorectal cancer

It has been demonstrated that interleukin 24 (IL-24, also called melanoma differentiation associated gene 7) exerts antitumor activity. In this study, we investigated whether oncolytic adenovirus-mediated gene transfer of IL-24 could induce strong antitumor activity. A tumor-selective replicating adenovirus expressing IL-24 (ZD55-IL-24) was constructed by insertion of an IL-24 expression cassette into the ZD55 vector, which is based on deletion of the adenoviral E1B 55-kDa gene. ZD55-IL-24 could express substantially more IL-24 than Ad-IL-24 because of replication of the vector. It has been shown that ZD55-IL-24 exerted a strong cytopathic effect and significant apoptosis in tumor cells with p53 dysfunction. Moreover, no cytotoxic and apoptotic effects could be seen in normal cells infected with ZD55-IL-24. Expression of IL-24 did not interfere with viral replication induced by oncolytic adenovirus. Activation of caspase 3 and caspase 9, and induction of bax gene expression, were involved in tumor cell apoptosis induced by ZD55-IL-24. Treatment of established tumors with ZD55-IL-24 showed much stronger antitumor activity than that induced by ONYX-015 or Ad-IL- 24. These data indicated that oncolytic adenovirus expressing IL-24 could exert potential antitumor activity and offer a novel approach to cancer therapy.     

Concurrent delivery of GM-CSF and B7-1 using an oncolytic adenovirus elicits potent antitumor effect

Oncolytic adenoviral vectors are currently being developed as biologic anticancer agents. Coupling the lytic function of an oncolytic adenovirus (Ad) with its ability as a transgene delivery system represents a powerful extension of this methodology. A clear advantage is the amplification of a therapeutic gene, as replicating vectors would be able to infect and deliver the gene of interest to neighboring cells. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is one of the most potent stimulators of a specific and long-lasting antitumor immunity and its important role in the maturation of antigen-presenting cells to induce T-cell activation has been well documented. Similarly, the B7 family has also been shown to play an integral role in mediating an antitumor response. Most tumor cells, however, lack the expression of these costimulatory molecules on their surface, thus escaping immune system recognition. To increase the antitumor effect of an oncolytic Ad, we have generated an E1B 55 kDa-deleted oncolytic adenoviral vector, YKL-GB, that expresses both GM-CSF and B7-1. The therapeutic efficacy of YKL-GB Ad was evaluated in immunocompetent mice bearing murine melanoma B16-F10 tumors. Significant inhibition of tumor growth was seen in mice treated with YKL-GB compared to those treated with the analogous vector, YKL-1. Moreover, YKL-GB oncolytic Ad demonstrated enhanced antitumor activity and higher incidences of tumor regression compared to a replication-incompetent Ad, dl-GB, which coexpresses GM-CSF and B7-1. Localized GM-CSF and B7-1 gene transfer also conferred long-lasting immunity against a tumor re-challenge. To establish that the observed antitumor effect is associated with the generation of a tumor-specific immune response, we carried out interferon-gamma enzyme-linked immune spot assay. We observed that YKL-GB induced significantly higher immune cell activation than YKL-1. Furthermore, immunohistochemical studies demonstrated robust dendritic cells and CD4(+)/CD8(+) T-cell infiltration in these mice compared to the YKL-1-treated groups. In agreement with these results, splenocytes from tumor-bearing mice treated with YKL-GB expressed high levels of the costimulatory and activation molecules. These findings demonstrate the effectiveness of enhancing the immune response against tumors with an oncolytic Ad expressing both GM-CSF and B7-1 and provide a potential therapeutic strategy for the management of neoplasia.     

Augmenting the antitumor effect of TRAIL by SOCS3 with double-regulated replicating oncolytic adenovirus in hepatocellular carcinoma

Aberrant JAK/STAT3 pathway has been reported to be related to hepatocellular carcinoma (HCC) in many cell lines. In this study, a double-regulated oncolytic adenovirus vector that can replicate and induce a cytopathic effect in alpha-fetoprotein (AFP)-positive HCC cell lines with p53 dysfunction was successfully constructed. Two therapeutic genes, suppressor of cytokine signaling 3 (SOCS3) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), were chosen and incorporated into this vector system, respectively. The combined treatment of AFP-D55-SOCS3 and AFP-D55-TRAIL (2:3 ratio) exhibited potent antitumor activity in AFP-positive HCC cell lines compared with any other treatment both in vitro and in vivo. Specific replication and low progeny yield in AFP-positive HCC cell lines rendered these double-regulated oncolytic adenoviruses remarkably safe. Our data demonstrated that restoration of SOCS3, which inhibits the JAK/STAT3 pathway, by AFP-D55-SOCS3 not only could antagonize HCC therapeutic resistance to TRAIL and adenoviruses, but could also induce cell cycle arrest in HCC cell lines. SOCS3 could down-regulate Cyclin D1 and anti-apoptotic proteins such as XIAP, Survivin, Bcl-xL, and Mcl-1, which are responsible for the synergistic inhibitory effects of AFP-D55-SOCS3 and AFP-D55-TRAIL. Dual gene and double-regulated oncolytic adenoviruses may provide safety and excellent antitumor effects for liver cancer, which is the advantage of a cancer-targeting gene virotherapy strategy.     

1alpha,25-Dihydroxyvitamin D3 potentiates cisplatin antitumor activity by p73 induction in a squamous cell carcinoma model

1alpha,25-Dihydroxyvitamin D3 (1,25D3) exhibits antitumor activity in a variety of cancers including squamous cell carcinoma (SCC). Intrinsic resistance of SCC cells to cisplatin was observed and led to the investigation into whether 1,25D3 sensitizes SCC cells to cisplatin. Pretreatment with 1,25D3 followed by cisplatin enhanced growth inhibition in SCC cells compared with 1,25D3 alone as assessed by cytotoxicity and in vitro clonogenic assays. In addition, 1,25D3 sensitized SCC cells to cisplatin-mediated apoptosis. Treatment of tumor-bearing C3H mice with 1,25D3 before cisplatin reduced clonogenic survival using in vivo excision clonogenic assay. These results were not observed in a 1,25D3-resistant SCC variant, indicating the critical role of 1,25D3 in sensitizing SCC cells to cisplatin. Further, a marked decrease in fractional tumor volume was observed when SCC tumor-bearing mice were treated with 1,25D3 before cisplatin compared with either agent administered alone. Cisplatin has been shown to modulate p73 protein level in certain cancer cells. Our data showed that p73 level was not affected by cisplatin but increased by 1,25D3 in SCC cells. Knocking down p73 by small interfering RNA protected SCC cells against 1,25D3 and cisplatin-mediated clonogenic cell kill and apoptosis. Increasing p73 protein level by knocking down UFD2a, which mediates p73 degradation, promoted 1,25D3 and cisplatin-mediated clonogenic cell kill. These results suggest that 1,25D3 potentiates cisplatin antitumor activity in vitro and in vivo in a SCC model system possibly through p73 induction and apoptosis. The combination treatment may provide a more effective therapeutic regimen in cancer treatment.     

Wnt信号通路与卵巢癌治疗新进展

Wnt通路是一条高度保守的传导通路,Wnt信号通路异常激活与肿瘤发生发展有密切关系。近年来,不少研究证明卵巢癌中存在异常激活的Wnt通路信号蛋白。该文复习了卵巢癌与Wnt通路相关的新近研究进展,对Wnt信号通路、其在卵巢癌发生发展的作用及Wnt通路中潜在的卵巢癌治疗新靶点做一综述,旨在为卵巢癌的临床治疗提供新思路。     

Inhibition of STAT3 signaling pathway by nitidine chloride suppressed the angiogenesis and growth of human gastric cancer

STAT3 has been strongly implicated in human malignancies, and constitutive activation of STAT3 serves a crucial role in cell survival, angiogenesis, immune evasion, and inflammation. In this study, we showed that nitidine chloride, a natural phytochemical alkaloid derived from Zanthoxylum nitidum (Roxb) DC, exerts potent anticancer activity through STAT3 signaling cascade. Nitidine chloride dose dependently suppressed VEGF-induced endothelial cell proliferation, migration, and tubular structure formation in vitro and dramatically reduced VEGF-triggered neovascularization in mouse cornea and Matrigel plugs in vivo. This angiogenesis inhibition mediated by nitidine chloride was well interpreted by the suppression of Janus kinase 2/STAT3 signaling and STAT3 DNA-binding activity in endothelial cells. Furthermore, nitidine chloride suppressed the constitutively activated STAT3 protein, its DNA-binding activity, and the expression of STAT3-dependent target genes, including cyclin D1, Bcl-xL, and VEGF in human gastric cancer cells. Consistent with the earlier findings, nitidine chloride inhibited gastric tumor cell growth and induced tumor cell apoptosis in vitro and effectively suppressed the volume, weight, and microvessel density of human SGC-7901 gastric solid tumors (n = 8) at a dosage of 7 mg/kg/d (intraperitoneal injection). Immunohistochemistry and Western blot analysis further revealed that the expression of STAT3, CD31, and VEGF protein in xenografts was remarkably decreased by the alkaloid. Taken together, we propose that nitidine chloride is a promising anticancer drug candidate as a potent STAT3 signaling inhibitor.     

Genomic DNA damage and ATR-Chk1 signaling determine oncolytic adenoviral efficacy in human ovarian cancer cells

Oncolytic adenoviruses replicate selectively within and lyse malignant cells. As such, they are being developed as anticancer therapeutics. However, the sensitivity of ovarian cancers to adenovirus cytotoxicity varies greatly, even in cells of similar infectivity. Using both the adenovirus E1A-CR2 deletion mutant dl922-947 and WT adenovirus serotype 5 in a panel of human ovarian cancer cell lines that cover a 3-log range of sensitivity, we observed profound overreplication of genomic DNA only in highly sensitive cell lines. This was associated with the presence of extensive genomic DNA damage. Inhibition of ataxia telangiectasia and Rad3-related checkpoint kinase 1 (ATR-Chk1), but not ataxia telangiectasia mutated (ATM), promoted genomic DNA damage and overreplication in resistant and partially sensitive cells. This was accompanied by increased adenovirus cytotoxicity both in vitro and in vivo in tumor-bearing mice. We also demonstrated that Cdc25A was upregulated in highly sensitive ovarian cancer cell lines after adenovirus infection and was stabilized after loss of Chk1 activity. Knockdown of Cdc25A inhibited virus-induced DNA damage in highly sensitive cells and blocked the effects of Chk1 inhibition in resistant cells. Finally, inhibition of Chk1 decreased homologous recombination repair of virus-induced genomic DNA double-strand breaks. Thus, virus-induced host cell DNA damage signaling and repair are key determinants of oncolytic adenoviral activity, and promoting unscheduled DNA synthesis and/or impeding homologous recombination repair could potentiate the effects of oncolytic adenoviruses in the treatment of ovarian cancer.     

STAT3 & Cytochrome P450 2C9: A novel signaling pathway in liver cancer stem cells

Although cancer stem cells (CSCs) are believed to be the key drivers in tumor growth and resistance to therapy, the specific signaling of CSCs is largely unknown. In this study, we evaluated the roles of hypoxia and STAT3 signaling on the treatment resistance of CSCs. Side population (SP) cell analysis and sorting were used to detect subpopulations that function as CSCs. Huh-7 cells, doxorubicin, sulfaphenazole (a CYP2C9 inhibitor), and AG490 (a STAT3 inhibitor) were used in this study. Cell growth and apoptosis were assessed using MTS assays, and apoptotic and kinase signaling pathways were explored by immunoblotting. Treatment with IL-6 induced STAT3 activation more significantly in SP than non-SP cells. Hypoxia induced SP cell proliferation, and microarray analysis showed that the expression of CYP2C9 was significantly increased in hypoxic than normoxic SP cells. Although hypoxic SP cells were less sensitive to doxorubicin-induced apoptosis, pretreatment with sulfaphenazole sensitized hypoxic SP cells to doxorubicin cytotoxicity. These results indicate that STAT3 is critical for CSC survival and hypoxia-inducible CYP2C9 expression is responsible the doxorubicin resistance of CSCs under hypoxic conditions. Thus, the selective inhibition of CYP2C9 and STAT3 may be implicated in the sensitization of CSCs to anti-cancer treatment, particularly in advanced cases.     

Pentoxifylline inhibits melanoma tumor growth and angiogenesis by targeting STAT3 signaling pathway

Pentoxifylline (PTX), a phosphodiesterase inhibitor, has been shown to have anti-metastatic or anti-angiogenic activity against many human cancers. However, the underlying mechanisms are unknown. In this study, we report that, PTX at sub-toxic doses can inhibit melanoma tumor growth and angiogenesis by targeting the STAT3 signaling pathway. Despite minimal cytotoxicity against normal cells, PTX suppressed phosphorylation and DNA binding of STAT3 in a dose-dependent manner. Also, PTX inhibited phosphorylation of the upstream kinases JAK1 and JAK2 and increased the expression of pSHP2 phosphatase. Expression of various STAT3 regulated gene products, such as cylinD1, CDK6, cMyc, BclXL, and VEGF was downregulated following PTX treatment. Tumor microenvironment favours tumor growth and metastasis. PTX alters tumor microenvironment by limiting IL-6 secretion and also by disrupting VEGF–VEGFR2 autocrine/paracrine signaling. PTX treatment significantly inhibited tumor growth and angiogenesis in intra-dermal xenograft mouse model in vivo without having any visible toxicity. These findings identified STAT3 signaling as a target of PTX and have thus, augmented its potential application in the treatment of melanoma and other cancers.     

Antroquinonol blocks Ras and Rho signaling via the inhibition of protein isoprenyltransferase activity in cancer cells

Antroquinonol is the smallest anticancer molecule isolated from Antrodia camphorata thus far. The ubiquinone-like structure of Antroquinonol exhibits a broad spectrum of activity against malignancies in vivo and in vitro. However, the mechanism of action of Antroquinonol remains unclear. Here, we provide evidence that Antroquinonol plays a role in the inhibition of Ras and Ras-related small GTP-binding protein functions through the inhibition of protein isoprenyl transferase activity in cancer cells. Using cell line-based assays, we found that the inactive forms of Ras and Rho proteins were significantly elevated after treatment with Antroquinonol. We also demonstrated that Antroquinonol binds directly to farnesyltransferase and geranylgeranyltransferase-I, which are key enzymes involved in activation of Ras-related proteins, and inhibits enzymes activities in vitro. Furthermore, a molecular docking analysis illustrated that the isoprenoid moiety of Antroquinonol binds along the hydrophobic cavity of farnesyltransferase similar to its natural substrate, farnesyl pyrophosphate. In contrast, the ring structure of Antroquinonol lies adjacent to the Ras-CAAX motif-binding site on farnesyltransferase. The molecular docking study also showed a reasonable correlation with the IC₅₀ values of Antroquinonol analogues. We also found that the levels of LC3B-II and the autophagosome-associated LC3 form were also significantly increased in H838 after Antroquinonol administration. In conclusion, Antroquinonol inhibited Ras and Ras-related GTP-binding protein activation through inhibition of protein isoprenyl transferase activity, leading to activation of autophagy and associated mode of cell death in cancer cells.     

Immune gene-viral therapy with triplex efficacy mediated by oncolytic adenovirus carrying an interferon-gamma gene yields efficient antitumor activity in immunodeficient and immunocompetent mice.

Among numerous gene therapeutic strategies for cancer treatment, gene transfer by conditionally replicative adenovirus (CRAd) of interferon-gamma (IFN-gamma) may be useful because of the possibility that it will yield IFN-gamma-mediated antiangiogenesis, immune responses, and CRAd-mediated oncolysis. In this study, we constructed a human TERT promoter-mediated oncolytic adenovirus targeting telomerase-positive cancers and armed with a mouse or human IFN-gamma gene to generate novel immune gene-viral therapeutic systems, CNHK300-mIFN-gamma and CNHK300-hIFN-gamma, respectively. The systems can specifically target, replicate in, and lyse cancer cells, while sparing normal cells. The advantage of these systems is that the number of transgene copies and their expression increase markedly via viral replication within infected cancer cells, and replicated viral progeny can then infect additional cancer cells within the tumor mass. CNHK300-mIFN-gamma induced regression of xenografts in liver cancer models in both immunodeficient and immunocompetent mice by triplex mechanisms including selective oncolysis, antiangiogenesis, and immune responses. We conclude that combining immune gene therapy and oncolytic virotherapy can enhance antitumor efficacy as a result of synergism between CRAd oncolysis and transgene composite antitumor responses.     

Systemic delivery of a novel liver-detargeted oncolytic adenovirus causes reduced liver toxicity but maintains the antitumor response in a breast cancer bone metastasis model

We are interested in developing oncolytic adenoviruses for the treatment of bone metastasis of cancer. A key limitation of systemic delivery of oncolytic adenovirus type 5 (Ad5) is that the majority of the virus is taken up by the liver, causing liver damage and systemic toxicity. Given that Ad5 hexon binding with blood coagulation factor X is a key factor in liver sequestration, and that a rare serotype, Ad48, has a diminished capacity to bind with factor X, we have generated mHAd.luc2, a novel hexon-chimeric oncolytic adenovirus. To create mHAd.luc2, seven hypervariable regions of Ad5 hexon were substituted with the corresponding regions from Ad48. Compared with Ad5-based oncolytic virus Ad.luc2, intravenous injection of mHAd.luc2 into nude mice resulted in significantly reduced liver uptake. A single high dose (1.0×10(11) viral particles/mouse) of Ad.luc2 resulted in 100% animal death by day 3; whereas none of the mice died in the mHAd.luc2 group. Liver enzyme and liver pathology studies indicated that mHAd.luc2 induced significantly less liver toxicity compared with Ad.luc2. Both mHAd.luc2 and Ad.luc2 exhibited similar binding with breast tumor cells, whereas in the presence of factor X, mHAd.luc2 binding was reduced. Both mHAd.luc2 and Ad.luc2 had nearly equal replication potential in breast cancer cells in vitro. Intravenous injection of mHAd.luc2 and Ad.luc2 into nude mice bearing bone metastases resulted in uptake of the viruses into skeletal tumors, and induced significant inhibition of established bone metastases. Thus, liver-detargeted oncolytic adenovirus can be developed for the treatment of breast cancer bone metastasis.     

Viral genome DNA/lipoplexes elicit in situ oncolytic viral replication and potent antitumor efficacy via systemic delivery

Modifying the viral genome to express potent and cancer-selective therapeutic genes has enhanced the role of adenoviruses (Ads) in cancer molecular therapeutics. However, the efficacy of Ad systemic delivery in vivo is limited by neutralizing antibodies, short blood circulation time, and high levels of nonspecific liver uptake resulting in hepatotoxicity. We therefore investigated the systemic delivery of tumor necrosis factor-related apoptosis-inducing ligand-expressing oncolytic Ad genome DNA (pmT-d19/stTR) via lipid envelopment as an alternative approach for cancer virotherapy in an orthotopic lung cancer model. Cationic liposomes (DOTAP/DOPE) were complexed with pmT-d19/stTR to generate pmT-d19/stTR + DOTAP/DOPE with the average diameter of which was 143.3 ± 5.7 nm at the optimal DNA:lipid ratio (1:6). Systemic administration of pmT-d19/stTR + DOTAP/DOPE elicited highly effective antitumor responses in vivo, with tumor volumes decreasing 94.5%, 90.5%, and 92.4% compared to phosphate buffered saline-, naked Ad (mT-d19/stTR)-, or pmT-d19/stTR-treated groups, respectively. Additionally, innate immune responses and Ad-specific neutralizing antibodies were significantly decreased in pmT-d19/stTR + DOTAP/DOPE-treated mice compared to those in the mT-d19/stTR-treated group. The biodistribution profile analyzed by quantitative-PCR and immunohistochemical analysis demonstrated that viral replication occurred preferentially in tumor tissues. Moreover, the viral genome tumor-to-liver ratio was significantly elevated in pmT-d19/stTR + DOTAP/DOPE-treated mice, which was 934- and 27-fold greater than the mT-d19/stTR- and pmT-d19/stTR-treated mice, respectively. These results demonstrate that systemic delivery of oncolytic viral genome DNA with liposomes is a powerful alternative to naked Ad, overcoming the limited clinical applicability of conventional Ads and enabling effective treatment of disseminated metastatic tumors.     

STAT1 - Caspase3信号通路在创伤性股骨头坏死中的作用机制分析

目的 分析信号传导子及转录激活子1( STAT1 )-含半胱氨酸的天冬氨酸蛋白水解酶3( Caspase3 )信号通路在创伤性股骨头坏死中的作用机制,以期能为后期临床治疗创伤性股骨头坏死提供指导.方法 采用前瞻性研究方法 ,选取2020年1月至2020年11月期间河南科技大学第一附属医院收治的行股骨头穿刺活检手术及髋关...     

基于STAT3信号通路探讨艾司洛尔对脓毒症大鼠急性肝损伤的保护作用

目的探讨艾司洛尔(ES)对脓毒症大鼠急性肝损伤的保护作用及相关信号通路。方法48只雄性SPF级大鼠随机分为假手术(Sham)组、盲肠结扎穿孔(CLP+NS)组和艾司洛尔干预(CLP+ES)组(每组16只)。Sham组采用盲肠探查术,CLP+NS组、CLP+ES组采用CLP法建立脓毒症大鼠模型。CLP+ES组经颈内静脉微量泵入ES稀释液6 h,Sham组和CLP+NS组给予等质量生理盐水。术后6 h、24 h各组分别处死8只大鼠。采用HE染色,观察脓毒症大鼠肝组织形态学变化,生化分析仪检测血清肝功能指标,酶联免疫吸附法(ELISA)检测肝组织中炎性细胞因子水平,Western blot检测肝组织中STAT3信号通路标志蛋白的表达。结果CLP+NS组脓毒症大鼠肝组织炎性细胞浸润明显,而CLP+ES组炎性细胞减少,肝细胞坏死程度好转。术后6 h、24 h,CLP+NS组血清天冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)和肝组织匀浆中高迁移率族蛋白B-1(HMGB-1)、白细胞介素-6(IL-6)均升高(P<0.05);而CLP+ES组较CLP+NS组均降低(P<0.05)。术后6 h,与CLP+NS组比较,CLP+ES组脓毒症大鼠肝组织中磷酸化信号转导和转录激活因子3(p-STAT3)表达水平明显下降(P<0.05),细胞因子信号转导抑制因子3(SOCS3)表达明显上升(P<0.05)。术后24 h,CLP+ES组上述蛋白表达与CLP+NS组比较差异无统计学意义(P>0.05)。结论艾司洛尔通过抑制STAT3信号通路,抑制炎性细胞因子释放,从而发挥对脓毒症大鼠急性肝损伤的保护作用。