p53 activation enhances the sensitivity of non-small cell lung cancer to the combination of SH003 and docetaxel by inhibiting de novo pyrimidine synthesis

BACKGROUND

Identifying molecular biomarkers for predicting responses to anti-cancer drugs can enhance treatment precision and minimize side effects. This study investigated the novel cancer-targeting mechanism of combining SH003, an herbal medicine, with docetaxel in non-small cell lung cancer (NSCLC) cells. Also, the present study aimed to identify the genetic characteristics of cancer cells susceptible to this combination.

METHODS

Cell viability was analyzed by WST-8 assay. Apoptosis induction, BrdU incorporation, and cell cycle analysis were performed using flow cytometry. Metabolites were measured by LC-MS/MS analysis. Real-time PCR and western blotting evaluated RNA and protein expression. DNA damage was quantified through immunofluorescence. cBioPortal and GEPIA data were utilized to explore the mutual co-occurrence of TP53 and UMPS and UMPS gene expression in NSCLC.

RESULTS

The combination treatment suppressed de novo pyrimidine nucleotide biosynthesis by reducing the expression of related enzymes. This blockade of pyrimidine metabolism led to DNA damage and subsequent apoptosis, revealing a novel mechanism for inducing lung cancer cell death with this combination. However, some lung cancer cells exhibited distinct responses to the combination treatment that inhibited pyrimidine metabolism. The differences in sensitivity in lung cancer cells were determined by the TP53 gene status. TP53 wild-type lung cancer cells were effectively inhibited by the combination treatment through p53 activation, while TP53 mutant- or null-type cells exhibited lower sensitivity.

CONCLUSIONS

This study, for the first time, established a link between cancer cell genetic features and treatment response to simultaneous SH003 and docetaxel treatment. It highlights the significance of p53 as a predictive factor for susceptibility to this combination treatment. These findings also suggest that p53 status could serve as a crucial criterion in selecting appropriate therapeutic strategies for targeting pyrimidine metabolism in lung cancer.

Network pharmacology study to explore the multiple molecular mechanism of SH003 in the treatment of non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is one of the leading causes of human death worldwide. Herbal prescription SH003 has been developed to treat several cancers including NSCLC. Due to the multi-component nature of SH003 with multiple targets and pathways, a network pharmacology study was conducted to analyze its active compounds, potential targets, and pathways for the treatment of NSCLC.

METHODS

We systematically identified oral active compounds within SH003, employing ADME criteria-based screening from TM-MC, OASIS, and TCMSP databases. Concurrently, SH003-related and NSCLC-associated targets were amalgamated from various databases. Overlapping targets were deemed anti-NSCLC entities of SH003. Protein-protein interaction networks were constructed using the STRING database, allowing the identification of pivotal proteins through node centrality measures. Empirical validation was pursued through LC-MS analysis of active compounds. Additionally, in vitro experiments, such as MTT cell viability assays and western blot analyses, were conducted to corroborate network pharmacology findings.

RESULTS

We discerned 20 oral active compounds within SH003 and identified 239 core targets shared between SH003 and NSCLC-related genes. Network analyses spotlighted 79 hub genes, including TP53, JUN, AKT1, STAT3, and MAPK3, crucial in NSCLC treatment. GO and KEGG analyses underscored SH003's multifaceted anti-NSCLC effects from a genetic perspective. Experimental validations verified SH003's impact on NSCLC cell viability and the downregulation of hub genes. LC-MS analysis confirmed the presence of four active compounds, namely hispidulin, luteolin, baicalein, and chrysoeriol, among the eight compounds with a median of > 10 degrees in the herb-compounds-targets network in SH003. Previously unidentified targets like CASP9, MAPK9, and MCL1 were unveiled, supported by existing NSCLC literature, enhancing the pivotal role of empirical validation in network pharmacology.

CONCLUSION

Our study pioneers the harmonization of theoretical predictions with practical validations. Empirical validation illuminates specific SH003 compounds within NSCLC, simultaneously uncovering novel targets for NSCLC treatment. This integrated strategy, accentuating empirical validation, establishes a paradigm for in-depth herbal medicine exploration. Furthermore, our network pharmacology study unveils fresh insights into SH003's multifaceted molecular mechanisms combating NSCLC. Through this approach, we delineate active compounds of SH003 and target pathways, reshaping our understanding of its therapeutic mechanisms in NSCLC treatment.

Synergistic and Additive Effects of Herbal Medicines in Combination with Chemotherapeutics: A Scoping Review

BACKGROUND

Natural products are increasingly gaining interest as potential new drug candidates for cancer treatment. Herbal formula, which are combinations of several herbs, are primarily used in East Asia and have a long history of use that continues today. Recently, research exploring the combination of herbal formulas and chemotherapy for cancer treatment has been on the rise.

METHODS

This study reviewed research on the co-administration of herbal formulas and chemotherapy for cancer treatment. The databases PubMed, Embase, and Cochrane Library were used for article searches. The following keywords were employed: "Antineoplastic agents," "Chemotherapy," "Phytotherapy," "Herbal medicine," "Drug synergism," and "Synergistic effect." The selection process focused on studies that investigated the synergistic interaction between herbal formulas and chemotherapeutic agents.

RESULTS

Among the 30 studies included, 25 herbal formulas and 7 chemotherapies were used. The chemotherapy agents co-administered included cisplatin, 5-fluorouracil, docetaxel, doxorubicin, oxaliplatin, irinotecan, and gemcitabine. The types of cancer most frequently studied were lung, breast, and colon cancers. Most studies evaluating the anticancer efficacy of combined herbal formula and chemotherapy treatment were conducted in vitro or in vivo.

DISCUSSION

Most studies reported synergistic effects on cytotoxicity, apoptosis, and tumor growth inhibition. These effects were found to be associated with cell cycle arrest, anti-angiogenesis, and gene expression regulation. Further studies leading to clinical trials are required. Clinical experiences in East Asian countries could provide insights for future research.

Identifying synergistic combinations of Doxorubicin-Loaded polyquercetin nanoparticles and natural Products: Implications for breast cancer therapy

Combining chemotherapeutic agents with bioactive natural products is an attractive cancer treatment modality to reduce the dose and side effects of chemotherapy. Combination treatments with drugs having different mechanisms of action can also be beneficial in combatting the development of drug resistance by cancer cells. Nanoparticle (NP)-mediated drug delivery can further improve the therapeutic index of cytotoxic agents by enabling passive and/or active targeting to tumor tissues in vivo. Using doxorubicin (DOX) as a model chemotherapeutic agent, we developed three NP formulations based on polyquercetin (pQCT), an emerging nanocarrier platform. The NPs were co-assembled with DOX, pQCT, and either Pluronic P123, methoxy poly(ethylene glycol)-amine, or D-α-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS). Physicochemical characterization of the NPs revealed them to have a spherical morphology with high monodispersity, excellent drug loading capacity, and sustained drug release. Then, the NPs were evaluated in vitro to determine their potential synergism when combined with the bioactive natural products curcumin (CUR), tannic acid (TA), and thymoquinone (TQ) against breast cancer cells (MCF-7 and MDA-MB-231). Surprisingly, most of the combinations were found to be antagonistic. However, combinations containing CUR exhibited greater pro-apoptotic effects compared to the single agents, with polymer-modified pQCT NPs presenting as a promising nanoplatform for enhancing DOX's ability to promote cancer cell apoptosis. Our findings provide insights into the potential application of pQCT in nanomedicine, as well as the use of bioactive natural products in combination with DOX as a free agent and as an NP formulation in the treatment of breast cancer.

Gallic acid suppresses the progression of triple-negative breast cancer HCC1806 cells via modulating PI3K/AKT/EGFR and MAPK signaling pathways

Triple-negative breast cancer (TNBC) is a severe threat to women’s health because of its aggressive nature, early age of onset, and high recurrence rate. Therefore, in this study, we aimed to evaluate the anti-tumor effects of Gallic acid (GA) on the TNBC HCC1806 cells in vitro. The cell proliferation was detected by MTT and plate clone formation assays, cell apoptosis, cell cycle, and mitochondrial membrane potential (MMP) were analyzed by flow cytometry and Hoechst 33258 staining assays, and the intracellular reactive oxygen species (ROS) accumulation were also investigated. Real-Time PCR and western blot were examined to explore the mechanism of action. The results indicated that GA suppressed HCC1806 cells proliferation and promoted HCC1806 cells apoptosis. Meanwhile, GA treatment changed the morphology of the HCC1806 cells. In addition, GA blocked the HCC1806 cells cycle in the S phase, and it induced cells apoptosis accompanied by ROS accumulation and MMP depolarization. Real-Time PCR results suggested that GA increased Bax, Caspase-3, Caspase-9, P53, JINK and P38 mRNA expression, and decreased Bcl-2, PI3K, AKT and EGFR mRNA expression. Western blotting results suggested that GA increased Bax, cleaved-Caspase-3, cleaved-Caspase-9, P53, P-ERK1/2, P-JNK, P-P38 proteins expression, and decreased Bcl-2, P-PI3K, P-AKT, P-EGFR proteins expression. Furthermore, molecular docking suggested that GA has the high affinity for PI3K, AKT, EGFR, ERK1/2, JNK, and P38. In conclusion, GA could suppress HCC1806 cells proliferation and promote HCC1806 cells apoptosis through the mitochondrial apoptosis pathway and induces ROS generation which further inhibits PI3K/AKT/EGFR and activates MAPK signaling pathways. Our study will provide some new references for using GA in the treatment of TNBC.

SH003 and Docetaxel Show Synergistic Anticancer Effects by Inhibiting EGFR Activation in Triple-Negative Breast Cancer

Although many anticancer drugs have been developed for triple-negative breast cancer (TNBC) treatment, there are no obvious therapies. Moreover, the combination of epidermal growth factor receptor- (EGFR-) targeted therapeutics and classical chemotherapeutic drugs has been assessed in clinical trials for TNBC treatment, but those are not yet approved. Our serial studies for newly developed herbal medicine named SH003 provide evidence of its broad effectiveness in various cancers, especially on TNBC. The current study demonstrates a synergic effect of combinatorial treatment of SH003 and docetaxel (DTX) by targeting EGFR activation. The combinatorial treatment reduced the viability of both BT-20 and MDA-MB-231 TNBC cells, displaying the synergism. The combination of SH003 and DTX also caused the synergistic effect on apoptosis. Mechanistically, the cotreatment of SH003 and DTX inhibited phosphorylation of EGFR and AKT in both BT-20 and MDA-MB-231 cells. Moreover, our xenograft mouse tumor growth assays showed the inhibitory effect of the combinatorial treatment with no effect on body weight. Our immunohistochemistry confirmed its inhibition of EGFR phosphorylation in vivo. Collectively, combinatorial treatment of SH003 and DTX has a synergistic anticancer effect at a relatively low concentration by targeting EGFR in TNBC, indicating safety and efficacy of SH003 as adjuvant combination therapy with docetaxel. Thus, it is worth testing the combinatorial effect in clinics for treating TNBC.

State of the Art and Future Implications of SH003: Acting as a Therapeutic Anticancer Agent

Cancer ranks as the first leading cause of death globally. Despite the various types of cancer treatments, negative aspects of the treatments, such as side effects and drug resistance, have been a continuous dilemma for patients. Thus, natural compounds and herbal medicines have earned profound interest as chemopreventive agents for reducing burden for patients. SH003, a novel herbal medicine containing Astragalus membranaceus, Angelica gigas, and Trichosanthes kirilowii, showed the potential to act as an anticancer agent in previous research studies. A narrative review was conducted to present the significant highlights of the total 15 SH003 studies from the past nine years. SH003 has shown positive results in both in vivo and vitro studies against various types of cancer cells; furthermore, the first clinical trial was performed to identify the maximum tolerated dose among solid cancer patients. So far, the potential of SH003 as a chemotherapeutic agent has been well-documented in research studies; continuous work on SH003's efficacy and safety is required to facilitate better cancer patient care but is part of the knowledge needed to understand whether SH003 has the potential to become a pharmaceutical.

Analgesic Effect of SH003 and Trichosanthes kirilowii Maximowicz in Paclitaxel-Induced Neuropathic Pain in Mice

Pacliatxel is a taxol-based chemotherapeutic drug that is widely used to treat cancer. However, it can also induce peripheral neuropathy, which limits its use. Although several drugs are prescribed to attenuate neuropathies, no optimal treatment is available. Thus, in our study, we analyzed whether SH003 and its sub-components could alleviate paclitaxel-induced neuropathic pain. Multiple paclitaxel injections (cumulative dose 8 mg/kg, i.p.) induced cold and mechanical allodynia from day 10 to day 21 after the first injection in mice. Oral administration of SH003, an herbal mixture extract of Astragalus membranaceus, Angelica gigas, and Trichosantheskirilowii Maximowicz (Tk), dose-dependently attenuated both allodynia. However, when administered separately only Tk decreased both allodynia. The effect of Tk was shown to be mediated by the spinal noradrenergic system as intrathecal pretreatment with α₁- and α₂-adrenergic-receptor antagonists (prazosin and idazoxan), but not 5-HT_1/2, and 5-HT₃-receptor antagonists (methysergide and MDL-72222) blocked the effect of Tk. The spinal noradrenaline levels were also upregulated. Among the phytochemicals of Tk, cucurbitacin D was shown to play a major role, as 0.025 mg/kg (i.p.) of cucurbitacin D alleviated allodynia similar to 500 mg/kg of SH003. These results suggest that Tk should be considered when treating paclitaxel-induced neuropathic pain.

Herbal Prescription SH003 Alleviates Docetaxel-Induced Neuropathic Pain in C57BL/6 Mice

Docetaxel-based therapy has been applied to kill cancers including lung and breast cancers but frequently causes peripheral neuropathy such as mechanical allodynia. Lack of effective drugs for chemotherapy-induced peripheral neuropathy (CIPN) treatment leads us to find novel drugs. Here, we investigated whether and how novel anticancer herbal prescription SH003 alleviates mechanical allodynia in mouse model of docetaxel-induced neuropathic pain. Docetaxel-induced mechanical allodynia was evaluated using von Frey filaments. Nerve damage and degeneration in paw skin of mice were investigated by immunofluorescence staining. Neuroinflammation markers in bloodstream, lumbar (L4-L6) spinal cord, and sciatic nerves were examined by ELISA or western blot analysis. Docetaxel (15.277 mg/kg) was intravenously injected into the tail vein of C57BL/6 mice, and mechanical allodynia was followed up. SH003 (557.569 mg/kg) was orally administered at least 60 min before the mechanical allodynia test, and von Frey test was performed twice. Docetaxel injection induced mechanical allodynia, and SH003 administration restored withdrawal threshold. Meanwhile, degeneration of intraepidermal nerve fibers (IENF) was observed in docetaxel-treated mice, but SH003 treatment suppressed it. Moreover, docetaxel injection increased levels of TNF-α and IL-6 in plasma and expressions of phospho-NF-κB and phospho-STAT3 in both of lumbar spinal cord and sciatic nerves, while SH003 treatment inhibited those changes. Taken together, it is worth noting that TNF-α and IL-6 in plasma and phospho-NF-κB and phospho-STAT3 in spinal cord and sciatic nerves are putative biomarkers of docetaxel-induced peripheral neuropathy (DIPN) in mouse models. In addition, we suggest that SH003 would be beneficial for alleviation of docetaxel-induced neuropathic pain.

A Phase I Study to Evaluate the Safety of the Herbal Medicine SH003 in Patients With Solid Cancer

Background: Cancer is a major health problem worldwide and the leading cause of death in many countries. Preclinical studies have shown the therapeutic anticancer effects of SH003, a novel herbal medicine containing Astragalus membranaceus, Angelica gigas, and Trichosanthes kirilowii. The present study investigated the maximum tolerated dose of SH003 in patients with solid cancers. Methods: This open-label, dose-escalation trial used the traditional 3 + 3 dose-escalation design. Patients with solid cancers were recruited and administered 1 to 4 tablets of SH003 thrice daily for 3 weeks according to the dose level. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE). Dose-limiting toxicities (DLTs) were defined as Grade 3 or higher adverse events based on CTCAE. The maximum tolerated dose was defined as the highest dose at which no more than 1 of 6 patients experienced DLT. Results: The present study enrolled 11 patients. A total of 31 adverse events occurred. According to the CTCAE, all the observed adverse events were grade 2 or less and no adverse events of grade 3 or more corresponding to DLT occurred. Conclusion: The study results indicated that the maximum tolerated dose of SH003 was 4800 mg/day. A Phase 2 study is required to determine the efficacy of SH003 in patients with cancer at a dose of 4800 mg/day or less.

Phase I study to evaluate the maximum tolerated dose of the combination of SH003 and docetaxel in patients with solid cancer: A study protocol

INTRODUCTION

Cancer is the second leading cause of death, and the burden of cancer continues to grow globally. Research on the efficacy of combined administration of herbal medicine and anticancer drugs is also increasing. SH003 is a new herbal medicine composed of Astragalus membranaceus, Angelica gigas, and Trichosanthes kirilowii. SH003 alone up to 4800 mg daily was found to be safe. Preclinical studies have shown SH003 to have a synergistic effect with coadministration of anticancer drugs. This study aimed to determine the maximum tolerated dose of SH003 combined with docetaxel in patients with lung or breast cancer.

METHODS

This is an open-label, dose-escalation study to evaluate the safety of SH003 combined with docetaxel. Patients with lung or breast cancer will be recruited. The participants will be divided into 3 groups based on SH003 daily dose (2400, 3600, and 4800 mg); the medication will be taken orally for 21 days. The traditional 3 + 3 design will be adopted for the dose escalation. Dose-limiting toxicities are defined as grade 3 or 4 adverse events according to the Common Terminology Criteria for Adverse Events. The highest dose at which no more than 1 of the 6 patients experience dose-limiting toxicity will be determined as the maximum tolerated dose of SH003 combined with docetaxel.

DISCUSSION

This study investigates the safety of SH003 when combined with docetaxel. The results of this study will provide a safe dose range for conducting therapeutic exploratory trials.

TRIAL REGISTRATIONS

ClinicalTrials.gov NCT04360317.

SH003 activates autophagic cell death by activating ATF4 and inhibiting G9a under hypoxia in gastric cancer cells

In gastric cancer (GC), hypoxia is one of the greatest obstacles to cancer therapy. In this present study, we report that SH003, an herbal formulation, induces ER stress via PERK-ATF4-CHOP signaling in GC. SH003-mediated ER stress inhibits G9a, a histone methyltransferase, by reducing STAT3 phosphorylation and activates autophagy, indicating to the dissociation of Beclin-1 and autophagy initiation from Bcl-2/Beclin-1 complex. However, the inhibition of PERK and CHOP inhibited SH003-induced cell death and autophagy activation. Moreover, targeting autophagy using specific siRNAs of LC3B or p62 or the autophagy inhibitor 3-MA also inhibited SH003-induced cell death in GC. Interestingly, SH003 induces BNIP3-mediated autophagic cell death under hypoxia than normoxia in GC. These findings reveal that SH003-induced ER stress regulates BNIP3-induced autophagic cell death via inhibition of STAT3-G9a axis under hypoxia in GC. Therefore, SH003 may an important tumor therapeutic strategy under hypoxia-mediated chemo-resistance.

A Combinational Approach Towards Treatment of Breast Cancer: an Analysis of Noscapine-Loaded Polymeric Nanoparticles and Doxorubicin

Our aim in this study was to clarify the combination anticancer effect of Noscapine (Nos) loaded in a polymeric nanocarrier with Doxorubicin (Dox) on breast cancer cells. Nanoprecipitation method was used to prepare methoxy polyethylene glycol (mPEG), poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) containing Nos. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) were used to characterize the prepared Nos NPs. The anticancer activity of Nos NPs alone and in combination with Dox was assessed on 4T1 breast cancer cell line and in mice model. Spherical-shaped Nos NPs were prepared, with size of 101 ± 4.80 nm and zeta potential of - 15.40 ± 1 mV. Fourier transform infrared (FTIR) spectroscopy results demonstrated that Nos chemical structure was kept stable during preparation process. However, differential scanning calorimetric (DSC) thermogram proved that crystalline state of Nos changed to amorphous state in Nos NPs. The entrapment efficacy % (EE%) and drug loading % (DL%) of Nos NPs were about 87.20 ± 3.50% and 12.50 ± 2.30%, respectively. Synergistic anticancer effects of Nos both in free form (in hydrochloride form, Nos HCl) and Nos NPs form with Dox hydrochloride (Dox HCl) were observed on 4T1 cells. Combination of Nos NPs and Dox HCl inhibited tumor growth (68.50%) in mice more efficiently than Nos NPs (55.10%) and Dox HCl (32%) alone. Immunohistochemical (IHC) analysis of the tumor tissues confirmed antiangiogenic effect of Nos NPs. The findings highlighted efficacy of Nos NPs alone and in combination with Dox HCl on breast cancer tumors.

Single-arm, open-label, dose-escalation phase I study to evaluate the safety of a herbal medicine SH003 in patients with solid cancer: a study protocol

INTRODUCTION

Cancer is a major health problem worldwide and the leading cause of death in many countries. The number of patients with cancer and socioeconomic costs of cancer continues to increase. SH003 is a novel herbal medicine consisting of Astragalus membranaceus, Angelica gigas and Trichosanthes Kirilowii Maximowicz. Preclinical studies have shown that SH003 has therapeutic anticancer effects. The aim of this study is to determine the maximum tolerated dose of SH003 in patients with solid cancers.

METHODS AND ANALYSIS

This study is an open-label, dose-escalation trial evaluating the safety and tolerability of SH003. The traditional 3+3 dose-escalation design will be implemented. Patients with solid cancers will be recruited. According to dose level, the patients will receive one to four tablets of SH003, three times a day for 3 weeks. Toxicity will be evaluated using common terminology criteria for adverse events (CTCAE). Dose-limiting toxicities are defined as grade 3 or higher adverse events based on CTCAE. The maximum tolerated dose will be determined by the highest dose at which no more than one of six patients experiences dose-limiting toxicity.

ETHICS AND DISSEMINATION

This study has been approved by the institutional review board of the Ajou University Hospital (reference AJIRB-MED-CT1-16-311). The results of this study will be disseminated through a scientific journal and a conference.

TRIAL REGISTRATION NUMBER

NCT03081819; Pre-results.

DT-13 synergistically potentiates the sensitivity of gastric cancer cells to topotecan via cell cycle arrest in vitro and in vivo

Natural medicine has multi-levels, multi-paths and multi-targets, and an increasing number of reports have confirmed that the combination of natural medicine with chemotherapy drugs exhibit a significant synergistic effect. It is necessary to find drug combination strategies to enhance efficacy and reduce toxicity, which can relieve the restrictions on the use of several chemotherapy drugs that have serious toxicity. Our previous reports showed that DT-13 inhibits cancer proliferation, invasion, migration, metastasis, and angiogenesis and induces autophagy. In this study, we evaluated the anti-proliferation effect of DT-13 on a panel of 40 different cancer cell lines for the first time. Moreover, it is also the first time that the combination of DT-13 with 5 different chemotherapy drugs on 3 common cancer cells has been examined. We further confirmed that DT-13 enhanced the sensitivity of gastric cancer cells to topotecan (TPT) via cell cycle arrest in vitro and in vivo. Considering that TPT has been subjected to restriction because of its serious toxicity, DT-13 showed the ability to enhance its effect and reduce its toxicity, which could provide a strategy to reduce the toxic and clinical side effects of TPT.

SH003‑induced G1 phase cell cycle arrest induces apoptosis in HeLa cervical cancer cells

Cervical cancer is a prevalent disease that may lead to mortality in women. In spite of the development of common therapeutic agents to treat cancer, there are several limitations of their use owing to side effects and drug resistance, which may induce cancer recurrence. The anticancer effects of the new herbal mixture SH003 (comprising Astragalus membranaceus, Angelica gigas and Trichosanthes kirilowii Maximowicz) have been examined in various types of cancer. Thus, the present study hypothesized that SH003 may be an effective treatment for cervical cancer. SH003 treatment inhibited the growth of HeLa cells, whereas it did not affect the growth of rat intestinal epithelial cells. In addition, SH003 treatment increased the expression of apoptosis‑related proteins and promoted apoptotic cell death in HeLa cells. SH003 treatment also led to G1 phase arrest in HeLa cells. Furthermore, SH003 treatment induced the production of reactive oxygen species (ROS); however, ROS production did not appear to be related to SH003‑mediated apoptosis. Results from the present study indicated that the SH003‑induced inhibition of HeLa cell growth may be mediated through G1 phase arrest and extrinsic apoptosis, suggested that SH003 may be a potential treatment for cervical cancer.

SH003 induces apoptosis of DU145 prostate cancer cells by inhibiting ERK-involved pathway

Background

Herbal medicines have been used in cancer treatment, with many exhibiting favorable side effect and toxicity profiles compared with conventional chemotherapeutic agents. SH003 is a novel extract from Astragalus membranaceus, Angelica gigas, and Trichosanthes Kirilowii Maximowicz combined at a 1:1:1 ratio that impairs the growth of breast cancer cells. This study investigates anti-cancer effects of SH003 in prostate cancer cells.

Methods

SH003 extract in 30% ethanol was used to treat the prostate cancer cell lines DU145, LNCaP, and PC-3. Cell viability was determined by MTT and BrdU incorporation assays. Next, apoptotic cell death was determined by Annexin V and 7-AAD double staining methods. Western blotting was conducted to measure protein expression levels of components of cell death and signaling pathways. Intracellular reactive oxygen species (ROS) levels were measured using H₂DCF-DA. Plasmid-mediated ERK2 overexpression in DU145 cells was used to examine the effect of rescuing ERK2 function. Results were analyzed using the Student’s t-test and P-values < 0.05 were considered to indicate statistically-significant differences.

Results

Our data demonstrate that SH003 induced apoptosis in DU145 prostate cancer cells by inhibiting ERK signaling. SH003 induced apoptosis of prostate cancer cells in dose-dependent manner, which was independent of androgen dependency. SH003 also increased intracellular ROS levels but this is not associated with its pro-apoptotic effects. SH003 inhibited phosphorylation of Ras/Raf1/MEK/ERK/p90RSK in androgen-independent DU145 cells, but not androgen-dependent LNCaP and PC-3 cells. Moreover, ERK2 overexpression rescued SH003-induced apoptosis in DU145 cells.

Conclusions

SH003 induces apoptotic cell death of DU145 prostate cancer cells by inhibiting ERK2-mediated signaling.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1490-5) contains supplementary material, which is available to authorized users.