Zhenfeng Hong

Hedyotis diffusa Willd Inhibits Colorectal Cancer Growth in Vivo via Inhibition of STAT3 Signaling Pathway

Signal Transducer and Activator of Transcription 3 (STAT3), a common oncogenic mediator, is constitutively activated in many types of human cancers; therefore it is a major focus in the development of novel anti-cancer agents. Hedyotis diffusa Willd has been used as a major component in several Chinese medicine formulas for the clinical treatment of colorectal cancer (CRC). However, the precise mechanism of its anti-tumor activity remains largely unclear. Using a CRC mouse xenograft model, in the present study we evaluated the effect of the ethanol extract of Hedyotis diffusa Willd (EEHDW) on tumor growth in vivo and investigated the underlying molecular mechanisms. We found that EEHDW reduced tumor volume and tumor weight, but had no effect on body weight gain in CRC mice, demonstrating that EEHDW can inhibit CRC growth in vivo without apparent adverse effect. In addition, EEHDW treatment suppressed STAT3 phosphorylation in tumor tissues, which in turn resulted in the promotion of cancer cell apoptosis and inhibition of proliferation. Moreover, EEHDW treatment altered the expression pattern of several important target genes of the STAT3 signaling pathway, i.e., decreased expression of Cyclin D1, CDK4 and Bcl-2 as well as up-regulated p21 and Bax. These results suggest that suppression of the STAT3 pathway might be one of the mechanisms by which EEHDW treats colorectal cancer.

Scutellaria barbata D. Don Inhibits Tumor Angiogenesis via Suppression of Hedgehog Pathway in a Mouse Model of Colorectal Cancer

Angiogenesis, which plays a critical role during tumor development, is tightly regulated by the Sonic Hedgehog (SHH) pathway, which has been known to malfunction in many types of cancer. Therefore, inhibition of angiogenesis via modulation of the SHH signaling pathway has become very attractive for cancer chemotherapy. Scutellaria barbata D. Don (SB) has long been used in China to treat various cancers including colorectal cancer (CRC). Our published data suggested that the ethanol extract of SB (EESB) is able to induce apoptosis of colon cancer cells and inhibit angiogenesis in a chick embryo chorioallantoic membrane model. To further elucidate the precise mechanisms of its anti-tumor activity, in the present study we used a CRC mouse xenograft model to evaluate the effect of EESB on tumor growth and angiogenesis in vivo. Our current data indicated that EESB reduces tumor size without affecting on the body weight gain in CRC mice. In addition, EESB treatment suppresses the expression of key mediators of the SHH pathway in tumor tissues, which in turn resulted in the inhibition of tumor angiogenesis. Furthermore, EESB treatment inhibits the expression of vascular endothelial growth factor A (VEGF-A), an important target gene of SHH signaling and functioning as one of the strongest stimulators of angiogenesis. Our findings suggest that inhibition of tumor angiogenesis via suppression of the SHH pathway might be one of the mechanisms by which Scutellaria barbata D. Don can be effective in the treatment of cancers.

Hedyotis diffusa Willd extract suppresses Sonic hedgehog signaling leading to the inhibition of colorectal cancer angiogenesis

Sonic hedgehog (SHH) signaling pathway promotes the process of angiogenesis, contributing to the growth and progression of many human malignancies including colorectal cancer (CRC), which therefore has become a promising target for cancer chemotherapy. Hedyotis diffusa Willd (HDW), as a well-known traditional Chinese herbal medicine, has long been used in China for the clinic treatment of various cancers. Recently, we reported that HDW can inhibit colorectal cancer growth in vivo and in vitro via suppression of the STAT3 pathway. In addition, we demonstrated the anti-angiogenic activity of HDW in vitro. To further elucidate the mechanism of the tumoricidal activity of HDW, by using a CRC mouse xenograft model we evaluated the in vivo effect of the ethanol extract of HDW (EEHDW) on tumor angiogenesis, and investigated the underlying molecular mechanisms. We found that EEHDW could significantly reduce intratumoral microvessel density (MVD), indicating its activity of antitumor angiogenesis in vivo. EEHDW suppressed the activation of SHH signaling in CRC xenograft tumors since it significantly decreased the expression of key mediators of SHH pathway. EEHDW treatment inhibited the expression of the critical SHH signaling target gene VEGF-A as well as its specific receptor VEGFR2. Taken together, we propose for the first time that Hedyotis diffusa Willd inhibits colorectal cancer growth in vivo via inhibition of SHH-mediated tumor angiogenesis.

Electro-acupuncture at points of Zusanli and Quchi exerts anti-apoptotic effect through the modulation of PI3K/Akt signaling pathway

We evaluated the neuroprotective effect of electro-acupuncture (EA) on cerebral ischemia-reperfusion (IR) injury and deeply investigated the relationship between this neuroprotective effect and PI3K/Akt pathway. Rats underwent focal cerebral IR injured by suture method and received the in vivo therapeutic efficacy of EA at points of Zusanli(ST36) and Quchi(LI11) after the operation. We found that the EA treatment significantly (p<0.05) improved neurological deficit and cerebral infarction. Furthermore, EA profoundly activated PI3K/Akt signaling resulted in the inhibition of cerebral cell apoptosis in the ischemic penumbra. Simultaneously EA increased the expression of PI3K, p-Akt, p-Bad and Bcl-2 at the protein level and the expression of Bcl-2 at the mRNA level. On the contrary, EA inhibited the Bax and cleaved Caspase-3-positive expression. The selective PI3K inhibitor LY294002 compromised EA-induced neuroprotective effects and reduced the elevation of p-Akt, p-Bad and Bcl-2 levels. Our data suggested that the PI3K/Akt pathway played a critical role in mediating the neuroprotective effects of EA treatment at points of Zusanli and Quchi after the ischemic stroke.

Pien Tze Huang inhibits tumor cell proliferation and promotes apoptosis via suppressing the STAT3 pathway in a colorectal cancer mouse model.

Signal transducer and activator of transcription 3 (STAT3) plays a critical role in cell survival and proliferation. Constitutive activation of STAT3 is strongly correlated with pathogenesis of various types of malignant tumors including colorectal cancer (CRC), and therefore is a major focus in the development of anti-cancer agents. Pien Tze Huang (PZH), a well-known traditional Chinese formula prescribed already in the Ming Dynasty, has been demonstrated to be clinically effective in the treatment of CRC. However, the precise mechanism of its anti-cancer activity remains largely unknown. In the present study we evaluated the efficacy of PZH against tumor growth in vivo in the CRC mouse xenograft model, and investigated the underlying molecular mechanisms. We found that administration of PZH reduced tumor volume and tumor weight but had no effect on body weight gain in CRC mice, demonstrating that PZH can inhibit colon cancer growth in vivo without apparent adverse effect. We also observed that PZH treatment inhibited the phosphorylation level of STAT3 in tumor tissues. Consequently, the inhibitory effect of PZH on STAT3 activation resulted in the up-regulation of Bax/Bcl-2 ratio as well as down-regulation of Cyclin D1 and CDK4 expression, leading to the induction of apoptosis as well as the inhibition of cell proliferation. These results suggest that promotion of cancer cell apoptosis and inhibition of proliferation via suppression of STAT3 pathway might be one of the mechanisms by which PZH treats colorectal cancer.

Ursolic acid inhibits colorectal cancer angiogenesis through suppression of multiple signaling pathways.

Angiogenesis plays a critical role in the development of solid tumors by supplying nutrients and oxygen to support continuous growth of tumor as well as providing an avenue for hematogenous metastasis. Tumor angiogenesis is highly regulated by multiple intracellular signaling transduction cascades such as Hedgehog, STAT3, Akt and p70S6K pathways that are known to malfunction in many types of cancer including colorectal cancer (CRC). Therefore, suppression of tumor angiogenesis through targeting these signaling pathways has become a promising strategy for cancer chemotherapy. Ursolic acid (UA) is a major active compound present in many medicinal herbs that have long been used in China for the clinical treatment of various types of cancer. Although previous studies have demonstrated an antitumor effect for UA, the precise mechanisms of its anti-angiogenic activity are not well understood. To further elucidate the mechanism(s) of the tumorcidal activity of UA, using a CRC mouse xenograft model, chick embryo chorioallantoic membrane (CAM) model, the human colon carcinoma cell line HT-29 and human umbilical vein endothelial cells (HUVECs), in the present study we evaluated the efficacy of UA against tumor growth and angiogenesis in vivo and in vitro and investigated the underlying molecular mechanisms. We found that administration of UA significantly inhibited tumor volume but had no effect on body weight changes in CRC mice, suggesting that UA can suppress colon cancer growth in vivo without noticeable signs of toxicity. In addition, UA treatment reduced intratumoral microvessel density (MVD) in CRC mice, decreased the total number of blood vessels in the CAM model, and dose and time-dependently inhibited the proliferation, migration and tube formation of HUVECs, demonstrating UAs antitumor angiogenesis in vivo and in vitro. Moreover, UA treatment inhibited the expression of critical angiogenic factors, such as VEGF-A and bFGF. Furthermore, UA suppressed the activation of sonic hedgehog (SHH), STAT3, Akt and p70S6K pathways. Collectively, our findings suggest that inhibition of tumor angiogenesis via suppression of multiple signaling pathways might be one of the mechanisms whereby UA can be effective in cancer treatment.

Effects of Pien Tze Huang (片仔癀) on angiogenesis in vivo and in vitro

ObjectiveTo investigate the anti-angiogenic effects of Pien Tze Huang (片仔癀, PZH) in vivo and in vitro.MethodsHuman umbilical vein endothelial cells (HUVECs) were treated with 0 mg/mL, 0.25 mg/mL, 0.5 mg/mL, and 1 mg/mL of PZH for 24 h, 48 h and 72 h, respectively. Chicken embryo chorioallantoic membrane (CAM) model was used to evaluate in vivo angiogenesis. An ECMatrix gel system was used to evaluate in vitro angiogenesis by examining the tube formation of HUVECs. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine HUVEC viability. Cell density of HUVECs was observed by phasecontrast microscopy. HUVEC migration was determined by wound healing method. The mRNA and protein expression of vascular endothelial growth factor A (VEGF-A) and basic fibroblast growth factor (bFGF) in both HUVEC and human colon adenocarcinoma cells (HT-29) was examined by reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immune sorbent assay (ELISA), respectively.ResultsPZH treatment significantly reduced the total number of blood vessels compared with the untreated control in the chicken embryos and resulted in a significant decrease in capillary tube formation and cell density of HUVECs (P<0.05). In addition, treatment with 0.25–1 mg/mL of PZH for 24 h, 48 h, and 72 h respectively reduced cell viability by 9%–52%, 24%–87% or 25%–87%, compared with the untreated control cells (P<0.05). Moreover, PZH treatment decreased the migration of HUVECs. Furthermore, PZH dose-dependently suppressed the expression of VEGF-A and bFGF on both mRNA and protein levels (P<0.05).ConclusionPZH could inhibit angiogenesis in vivo in CAM model and in vitro on HUVECs, suggesting that inhibiting tumor angiogenesis might be one of the mechanisms by which PZH treats cancer.

Pien Tze Huang suppresses IL-6-inducible STAT3 activation in human colon carcinoma cells through induction of SOCS3

IL-6/STAT3 is one of the most critical cellular signal transduction pathways known to malfunction in colorectal cancer (CRC). As a target gene of signal transducer and activator of transcription 3 (STAT3) signaling, suppressor of cytokine signaling 3 (SOCS3) can be quickly induced by interleukin-6 (IL-6) stimulation but it then strongly inhibits IL-6-mediated STAT3 activation, functioning as a negative feedback regulator of the IL-6/STAT3 pathway. Aberrant activation of STAT3 and/or reduced expression of SOCS are strongly correlated with carcinogenesis, which therefore becomes a promising target for the development of novel anticancer chemotherapies. Pien Tze Huang (PZH) is a well-known traditional Chinese formula that was first prescribed by a royal physician 450 years ago in the Ming Dynasty. It has been used in China and Southeast Asia for centuries as a folk remedy for various types of cancer including CRC. However, the precise mechanism of its antitumor activity remains largely unclear. In the present study, we found that PZH could significantly and dose-dependently inhibit IL-6-mediated increase of STAT3 phosphorylation levels and transcriptional activity in the human colon carcinoma HT-29 cells, resulting in the suppression of cell proliferation and the induction of apoptosis. In addition, PZH treatment profoundly inhibited IL-6-induced upregulation of cyclin D1 and Bcl-2, two key target genes of the STAT3 pathway. Moreover, PZH treatment increased the expression of SOCS3. These results suggest that PZH could effectively inhibit proliferation and promote apoptosis of human colon carcinoma cells via modulation of the IL-6/STAT3 signaling pathway and its target genes.

Patrinia scabiosaefolia extract suppresses proliferation and promotes apoptosis by inhibiting the STAT3 pathway in human multiple myeloma cells.

Signal transducer and activator of transcription 3 (STAT3) plays an important role in tumor cell survival and proliferation and thus has become a major focus in the development of anti-cancer therapies. Patrinia scabiosaefolia has been used for the treatment of various types of cancer. However, the precise mechanism of the anti-cancer activity of Patrinia scabiosaefolia remains unclear. In this study, we evaluated the effect of the ethanol extract of Patrinia scabiosaefolia (EEPS) on proliferation and apoptosis in human multiple myeloma U266 cells that persistently express phosphorylated STAT3, and investigated the possible molecular mechanisms mediating its biological effects. We found that EEPS inhibited the phosphorylation of STAT3 in U266 cells. Consequently, the inhibitory effect of EEPS on STAT3 activation resulted in the suppression of cell proliferation and the induction of cell apoptosis. Moreover, EEPS treatment inhibited the expression of cyclin D1 (a promoter of cell proliferation) and Bcl-2 (an inhibitor of apoptosis), two important target genes of the STAT3 signaling pathway. Our findings for the first time demonstrate that Patrinia scabiosaefolia inhibits proliferation and promotes the apoptosis of cancer cells via inhibition of the STAT3 pathway, which may in part explain its anti-cancer activity.

Scutellaria barbata D. Don induces G1/S arrest via modulation of p53 and Akt pathways in human colon carcinoma cells

Cancer cells are characterized by an uncontrolled increase in cell proliferation. G1 to S transition is one of the two main checkpoints used by cells to control the cell cycle progress and cell proliferation. G1/S progression is highly regulated by multiple intracellular signaling transduction cascades including Akt and p53 pathways, which therefore becomes a promising target for the development of novel anticancer therapy. Scutellaria barbata D. Don (SB) is a major component in many Chinese medicine formulas that have long been used in China to clinically treat various cancers including colorectal cancer (CRC). Recently, we reported that the ethanol extract of SB (EESB) is able to induce cancer cell apoptosis via activation of the mitochondrion-dependent pathway and inhibit tumor angiogenesis through suppression of Hedgehog signaling. To further elucidate the precise mechanisms of its antitumor activity, in the present study we evaluated the effect of EESB on the proliferation of human colon carcinoma HT-29 cells and investigated the underlying molecular mechanism. We found that EESB could inhibit the proliferation of HT-29 cells through blocking the G1/S cell cycle progression. In addition, EESB treatment profoundly promoted antiproliferative p21 expression, but inhibited the expression of pro-proliferative PCNA, cyclin D1 and CDK4 in HT-29 cells. Moreover, the phosphorylation/activation of Akt was significantly suppressed by EESB treatment, whereas that of p53 was enhanced. These results suggest that EESB could effectively induce G1/S arrest in human colon carcinoma cells via modulation of multiple cell cycle-related signaling pathways.