Spica prunellae promotes cancer cell apoptosis, inhibits cell proliferation and tumor angiogenesis in a mouse model of colorectal cancer via suppression of stat3 pathway

Abstract

BackgroundConstitutive activation of STAT3 is one of the major oncogenic pathways involved in the development of various types of malignancies including colorectal cancer (CRC); and thus becomes a promising therapeutic target. Spica Prunellae has long been used as an important component in many traditional Chinese medicine formulas to clinically treat CRC. Previously, we found that Spica Prunellae inhibits CRC cell growth through mitochondrion-mediated apoptosis. Furthermore, we demonstrated its anti-angiogenic activities in vivo and in vitro. To further elucidate the precise mechanism of the potential tumoricidal activity of Spica Prunellae, using a CRC mouse xenograft model, in this study we evaluated its therapeutic efficacy against CRC and investigated the underlying molecular mechanisms.MethodsCRC mouse xenograft model was generated by subcutaneous injection of human colon carcinoma HT-29 cells into nude mice. Animals were given intra-gastric administration with 6 g/kg of the ethanol extract of Spica Prunellae (EESP) daily, 5 days a week for 16 days. Body weight and tumor growth were measured every two days. Tumor growth in vivo was determined by measuring the tumor volume and weight. HT-29 cell viability was examined by MTT assay. Cell apoptosis and proliferation in tumors from CRC xenograft mice was evaluated via immunohistochemical staining (IHS) for TUNEL and PCNA, and the intratumoral microvessel density (MVD) was examined by using IHS for the endothelial cell-specific marker CD31. The activation of STAT3 was evaluated by determining its phosphorylation level using IHS. The mRNA and protein expression of Bcl-2, Bax, Cyclin D1, VEGF-A and VEGFR2 was measured by RT-PCR and IHS, respectively.ResultsEESP treatment reduced tumor volume and tumor weight but had no effect on body weight change in CRC mice; decreased HT-29 cell viability in a dose-dependent manner, suggesting that EESP displays therapeutic efficacy against colon cancer growth in vivo and in vitro, without apparent toxicity. In addition, EESP significantly inhibited the phosphorylation of STAT3 in tumor tissues, indicating its suppressive action on the activation of STAT3 signaling. Consequently, the inhibitory effect of EESP on STAT3 activation resulted in an increase in the pro-apoptotic Bax/Bcl-2 ratio, decrease in the expression of the pro-proliferative Cyclin D1 and CDK4, as well as down-regulation of pro-angiogenic VEGF-A and VEGFR-2 expression. Finally, these molecular effects led to the induction of apoptosis, the inhibition of cell proliferation and tumor angiogenesis.ConclusionsSpica Prunellae possesses a broad range of anti-cancer activities due to its ability to affect STAT3 pathway, suggesting that Spica Prunellae could be a novel potent therapeutic agent for the treatment of CRC.

Panax ginseng C.A. Meyer (Rg3) Ameliorates Gastric Precancerous Lesions in Atp4a−/− Mice via Inhibition of Glycolysis through PI3K/AKT/miRNA‐21 Pathway

“…Rg3 is an effective chemical trace component of ginseng with a C 42 H 72 O 13 chemical formula, a molecular weight of 784 Da, and pleiotropic capabilities that include antitumor effects. Previous studies have shown that Rg3 inhibits tumor cell growth, invasion, metastasis, and neovascularization [22][23][24]. Glycolytic regulation by Rg3, a potential anticancer mechanism, has been previously reported [25,26].…”

Chinese Herbal Medicines in the Treatment of IBD and Colorectal Cancer: A Review

“…frondosa water extractTNBS-induced colitis5-ASAp.o.Reversed symptoms of colitisImmune-suppressing (reduction of TNFα, NF-κB and neutrophil influx)[21]Changlu EnemaProtein immunization induced-UCSASPi.c.Reversed inflammatory response (macro- and microscopically)No data[22]Mixed herbal preparationDNCB and acetic acid-induced colitisSASPi.c.Improvement of colitis/abolished inflammationImmune-suppressing (reduction of TNFα, INFγ and IL-6)[23]β,β-demethylacrylshikoninHCT-116 tumor xenograftNonei.p.Reduction of tumor growthinducing apoptosis of tumor cells (increasing level of Bax/ decreasing level of Bcl-2)[41]Shikunshito-KamihoDMH-induced CRCNonein diet (p.o. )Reduction of aberrant crypt fociNo data[42]SophoridineSW480 tumor xenograft5-FUi.p.Reduction of tumor growthinducing apoptosis of tumor cells ( activation of caspase-3 dependent pathways)[45]Spica Prunellae ethanol extractHT-29 tumor xenograftNonep.oReduction of tumor growthinduction apoptosis of tumor cells/inhibition of tumor angiogenesis and proliferation[46] 5-ASA 5-aminosalicylic acid, 5-FU 5-fluorouracil, 6-MP 6-mercaptopurine, CRC colorectal cancer, DMH 1,2-dimethylhydrazine, DNCB 2,4-dinitrochlorobenzene, DS dextran sodium sulfate, DX dexamethasone, i.c. intracolonic, i.p.…”

Doxorubicin alters the mitochondrial dynamics machinery and mitophagy in the liver of treated animals

“…To determine whether mitochondrial fission was coupled to enhanced cell division in response to Doxinduced injury, we assessed the content of PCNA. PCNA is expressed in early G1 and S phase of the cell cycle and functions in cell cycle progression, DNA replication, and DNA repair and has previously been used as a marker of cell proliferation [30,31]. There was no difference in PCNA content between groups (1644.00 AE 110.73 vs. 1543.89 AE 120.94, P = 0.562), indicating that Dox does not induce cell proliferation in livers of treated animals, at least 24 h post-treatment.…”