Nitidine chloride inhibits hepatocellular carcinoma cell growth in vivo through the suppression of the JAK1/STAT3 signaling pathway

Abstract

Abstract. Signal transducer and activator of transcription 3 (STAT3) is persistently activated in cancer cells and contributes to malignant progression in various types of cancer. The Janus-activated kinase (JAK) family phosphorylates STAT3 in response to stimulation by cytokines or growth factors. The JAK1-STAT3 signaling pathway plays an important role in cell proliferation and apoptosis. Nitidine chloride (NC) is a benzophenanthridine alkaloid that has been reported as an antitumor agent due to its its inhibitory effects on topoisomerase I. Using a mouse xenograft model of hepatocellular carcinoma (HCC), this study aimed to evaluate the effects of NC on tumor growth in vivo and to elucidate the underlying mechanisms. The analysis of the effects of NC on apoptosis in HCC tumor xenografts in mice was carried out by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay; the expression of Bcl-2, Bax, cyclin-dependent kinase (CDK)4, cyclin D1, p21 and proliferating cell nuclear antigen (PCNA) was analyzed by immunohistochemistry; and the protein expression of JAK1 and STAT3 was examined by western blot analysis. Our results revealed that treatment with NC decreased the tumor volume and tumor weight, suggesting that NC inhibits HCC cell growth in vivo. In addition, NC blocked the activation of JAK1-STAT3 in the tumor tissues, which in turn resulted in the induction of cancer cell apoptosis and the inhibition of proliferation. Consequently, treatment with NC downregulated the expression of cyclin D1, CDK4 and Bcl-2 and increased the level of p21 and Bax. Our data provide a molecular basis for the antitumor activity of NC. IntroductionHepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide (1,2) and it has been reported that more than 600,000 individuals succumb to the disease each year (1). It is the second most common cause of cancer-related mortality in China, and 75% of known new cases and deaths in the Asia-Pacific region (3-5). Currently, the main treatment methods for liver cancer include surgical resection, radiotherapy and chemotherapy (4,6). Although surgical resection (which involves removing the tumor completely) offers the best prognosis for long-term survival, only 10-15% of patients are suitable for surgical resection, as the tumor may be too large, or may have grown into major blood vessels or other vital organs (7-9). Related data demonstrate that the percentage of HCC cells is already high at diagnosis with a high expression of the multidrug resistance gene and conventional chemotherapy of HCC fails to provide satisfactory remission and may cause serious side-effects (6,10). Thus, it is necessary to develop a novel effective drug for the treatment of HCC. Natural products have attracted much attention in the search for novel anticancer therapeutic agents as they have relatively few side-effects and have long been used as alternative therapies for various diseases, including cancer (11,12). Therefore, determining naturally occurrin...

Enrichment and analysis of quaternary alkaloids from Zanthoxylum simulans using weak cation exchange solid‐phase extraction coupled with LC–MS

“…Alkaloids, mainly found in the root or the stem bark of Z. simulans have been of immense interest due to their bioactivities, and quaternary alkaloids (QAs) as major alkaloids in this plant possess significant antitumour activities. For instance, nitidine displayed inhibitory activity on hepatic carcinoma cells by inhibiting the JAK1/STAT3 signal pathway in vitro , chelerythridine and sanguinarine showed dose‐dependent inhibitory activity by damaging the DNA of leukaemia carcinoma cells (L1210) in vitro , and fagaronine acted as angiogenesis inhibitors on leukaemia cancer cells . To explore the antitumour activities and the subsequent mechanisms of action regarding QAs from Z. simulans , one of the most important steps is to enrich and identify them from complex crude plant extracts.…”

The Contribution of Human OCT1, OCT3, and CYP3A4 to Nitidine Chloride–Induced Hepatocellular Toxicity

“…Meanwhile, the tumor-selective cytotoxicity of NC was found to be attributed to intercalation into DNA and inhibition of topoisomerase I and II (Gatto et al, 1996;Holden et al, 1999;Iwasaki et al, 2010;Pan et al, 2011). Additionally, NC could inhibit hepatocellular carcinoma cell growth in vivo (Liu et al, 2009;Liao et al, 2013). Thus, NC is thought to be a promising anticancer drug candidate.…”

“…DC (Arthur et al, 1959), was reported to have significant antimalarial (Gakunju et al, 1995), anti-human immunodeficiency virus (Tan et al, 1991), antimicrobial, and analgesic activities (Del Poeta et al, 1999;Hu et al, 2006). Recently, a number of studies found that NC showed anticancer potential in several tumor types, including osteosarcoma, gastric cancer, and liver cancer (Lv et al, 2011;Chen et al, 2012;Liao et al, 2013). The anticancer activity of NC was correlated with its ability to decrease cell growth, induce cell apoptosis, and arrest cell cycles in a variety of human cancer cell lines, such as MG-63 and KB osteosarcoma cell lines (Liu et al, 2007;Xu et al, 2011).…”

Aberrant expression of p-STAT3 in peripheral blood CD4+ and CD8+ T cells related to hepatocellular carcinoma development

“…It is the second cause of cancer-related mortality in China, and its prevalence is increasing, probably due to a high prevalence of hepatitis B (2,3). Surgical resection and liver transplantation are effective forms of therapy (4), but most patients have limited options and cannot afford these treatments.…”

“…In healthy cells, activation of the STAT3 protein is tightly controlled, in order to prevent deregulated gene transcription. STAT3 is constitutively activated in certain transformed cells (3). STAT3 activation is induced via phosphorylation of tyrosine (Tyr705), which allows STAT3 dimerization.…”