Siyu Chen

Clinical response to sunitinib as a multitargeted tyrosine-kinase inhibitor (TKI) in solid cancers: a review of clinical trials

Angiogenesis is an integral process in carcinogenesis, and molecular inhibitors of angiogenic factors are currently being tested as treatments for cancer. Sunitinib is an oral multitargeted tyrosine-kinase inhibitor that blocks activation through the stem cell-factor receptor (Kit) and platelet-derived growth-factor receptor. Sunitinib has shown potent antitumor activity against several solid tumors, including renal cell carcinoma, gastrointestinal stromal tumors, and neuroendocrine tumors in several Phase II/III trials. Recently, sunitinib has been used to treat other solid cancers, such as lung cancer, pancreatic cancer, chondrosarcoma, esophageal cancer, bladder cancer, glioma, and aggressive fibromatosis, and also showed potential efficacy in progression-free survival and overall survival. In this review, we examine the efficacy of sunitinib as a molecular-targeted therapy in patients with different types of solid cancers.

Efficacy and safety profile of combining agents against epidermal growth factor receptor or vascular endothelium growth factor receptor with gemcitabine-based chemotherapy in patients with advanced pancreatic cancer: A meta-analysis

OBJECTIVES Several clinical trials have been published on gemcitabine-based chemotherapy with or without addition of agents against epidermal growth factor receptor (EGFR) or vascular endothelium growth factor receptor (VEGFR) in patients with advanced pancreatic cancer, however, with diverse results. The objective of this study was to perform a meta-analysis of the published trials. METHODS The database of CENTRAL, MEDLINE and EMBASE were searched. Eligible studies were randomized clinical trials (RCTs) that evaluated the efficacy and safety profile of adding targeted agents against EGFR or VEGFR to gemcitabine-based chemotherapy in patients with advanced pancreatic cancer. The primary outcome was overall survival (OS) while secondary outcomes included progression free survival (PFS) and overall response rate (ORR). Toxicity profiles were also assessed. Review Manager 5.1 was used to perform the analysis. RESULTS Results reported from 6 RCTs involving 2733 patients were included in the analysis. Compared to gemcitabine-based chemotherapy alone, addition of an agent against EGFR resulted in significant longer OS [Hazard ratios (HR) 0.89 (0.79-0.99), p = 0.04] and longer PFS [HR 0.87 (0.79-0.97), p = 0.01], but no significant difference in ORR [RR 1.18 (0.82-1.70), p = 0.36]. The addition of an agent against VEGFR resulted in higher ORR [RR 1.54 (1.03-2.30), p = 0.04], but no advantage in OS [HR 0.95 (0.83-1.09), p = 0.47] or PFS [HR 0.97 (0.77-1.23), p = 0.82]. CONCLUSIONS Addition of an agent against EGFR to gemcitabine-based chemotherapy improved OS compared to gemcitabine-based chemotherapy alone in patients with advanced pancreatic cancer, while addition of an agent against VEGFR showed a modest improvement in ORR but not PFS and OS.

Arsenic sulfide as a potential anti‑cancer drug.

Arsenic sulfide (As4S4) is the main component of realgar, which is widely used in traditional Chinese medicine. Previous studies have shown the beneficial effects of As4S4 in the treatment of hematological malignant diseases, however, its effects on solid tumors have yet to be fully elucidated. The current study aimed to explore the anti-cancer effect and the mechanism of As4S4 on solid tumors in vitro and in vivo. Cells from four human solid tumor cell lines, including the MKN45 gastric cancer cell line, the A375 malignant melanoma cell line, the 8898 pancreatic carcinoma cell line and the HepG2 hepatocellular carcinoma cell line, were treated with As4S4 in vitro, using the L02 embryonic liver cells as a control. The efficacy of As4S4 was assessed in vivo using mice implanted with Lewis lung carcinoma cells. The results of the current study demonstrated that As4S4 significantly inhibited the proliferation of solid tumor cells in a dose- and time-dependent manner, but produced a less pronounced effect on L02 cells. Additionally, As4S4 was observed to induce apoptosis (including morphological changes and an enhanced sub-G1 population), which was accompanied by the activation of caspase-3 and −9. Furthermore, treatment with As4S4 significantly inhibited the growth of implanted tumors in mice. These results suggest that As4S4 possesses potent in vitro and in vivo antitumor activity via the induction of cell apoptosis.

Arsenic sulfide, the main component of realgar, a traditional Chinese medicine, induces apoptosis of gastric cancer cells in vitro and in vivo

Background Arsenic sulfide (As4S4), the main component of realgar, a traditional Chinese medicine, has shown antitumor efficacy in several tumor types, especially for acute promyelocytic leukemia. In this study, we aimed to explore the efficacy and mechanism of As4S4 in gastric cancer. Methods The effect of As4S4 on cell proliferation and apoptosis of gastric cancer cells was investigated by MTT assay, 4′,6-diamidino-2-phenylindole (DAPI) staining, and annexin V–fluorescein isothiocyanate/propidium iodide staining using gastric cancer cell lines AGS (harboring wild-type p53) and MGC803 (harboring mutant p53) in vitro. The expression of apoptosis-related proteins was measured by Western blotting, real-time polymerase chain reaction, and immunohistochemistry analysis. Mouse xenograft models were established by inoculation with MGC803 cells, and the morphology and the proportion of apoptotic cells in tumor tissues were detected by hematoxylin and eosin staining and TdT-mediated dUTP nick end labeling (TUNEL) assay, respectively. Results As4S4 inhibited the proliferation and induced apoptosis of AGS and MGC803 cells in a time- and dose-dependent manner. As4S4 upregulated the expression of Bax and MDM2 while downregulated the expression of Bcl-2. The expression of p53 increased significantly in the AGS cells but did not readily increase in the MGC803 cells, which harbored mutant p53. Pifithrin-α, a p53 inhibitor, blocked the modulation of As4S4 on AGS cells, but not on MGC803 cells. Using xenograft as a model, we showed that As4S4 suppressed tumor growth and induced apoptosis in vivo and that the expression of p53 increased accordingly. Conclusion As4S4 is a potent cytotoxic agent for gastric cancer cells, as it induced apoptosis both in vitro and in vivo through a p53-dependent pathway. Our data indicate that As4S4 may have therapeutic potential in gastric cancer.

Arsenic sulfide inhibits cell migration and invasion of gastric cancer in vitro and in vivo.

Background We previously showed that arsenic sulfide (As4S4) induced cell cycle arrest and apoptosis in several human solid tumor cell lines, including those of gastric cancer. In this study, we investigated the effect of As4S4 on the migration and invasion of gastric cancer cells both in vitro and in vivo. Methods The human gastric cancer cell lines AGS and MGC803 were selected as in vitro models. Wound-healing migration assay and Transwell invasion assay were carried out to determine the effects of As4S4 on cell migration and invasion. The expressions of E-cadherin, β-catenin, Sp1, KLF4, and VEGF were measured by Western blotting analysis. The activities of matrix metalloproteinase (MMP)-2 and MMP-9 in MGC803 cells were demonstrated by zymography assay. A mouse xenograft model was established by inoculation with MGC803 cells, then intraperitoneal injected with As4S4 for 3 weeks and monitored for body weight and tumor changes. Finally, the inhibition rate of tumor growth was calculated, and the expression of proteins and genes associated with tumor invasion and metastasis in tumor tissues were measured by immunohistochemistry, Western blotting, and real-time polymerase chain reaction assay. Results As4S4 significantly inhibited the migration and invasion of gastric cancer cell lines. The expression of E-cadherin and KLF4 was upregulated, while the expressions of β-catenin, VEGF, and Sp1 were downregulated following treatment with As4S4. Moreover, the protease activities of MMP-2 and MMP-9 were suppressed by As4S4 in MGC803 cells. Meanwhile, As4S4 effectively suppressed the abilities of tumor growth and invasion in the xenograft tumor model. We found that As4S4 upregulated the expression of E-cadherin and downregulated the expression of β-catenin, Sp1, VEGF, and CD34 in mouse tumor tissues, consistent with the results in vitro. Conclusion As4S4 inhibited the migration and invasion of gastric cancer cells by blocking tumor cell adhesion, decreasing the ability of tumor cells to destroy the basement membrane, and therefore suppressing their angiogenesis.

Arsenic sulfide combined with JQ1, chemotherapy agents, or celecoxib inhibit gastric and colon cancer cell growth

Background Arsenic compounds have modest cytotoxic activity in solid tumors. We investigated if arsenic sulfide (As4S4) in combination with other distinct agents could enhance its cytotoxic activity. Methods We used gastric and colon cancer cell lines to study the synergistic effect of As4S4 in combination with BRD4 inhibitor JQ1, or with chemotherapy drug cisplatin and irinotecan or with COX2 inhibitor celecoxib. We investigated the mechanism of the cytotoxic effect of these novel combinations. Results We found that when As4S4 was combined with JQ1, cisplatin, irinotecan or celecoxib, its cytotoxic activity was dramatically enhanced in both gastric and colon cancer cell lines. As4S4 and JQ1 inhibited BRD4 and c-Myc while activating p53 expression synergistically. As4S4 inhibited COX2 and cyclin D1 expression. When As4S4 was combined with chemotherapy drug cisplatin or COX2 inhibitor celecoxib, its inhibition of COX2, BCL2, and p38 expression was enhanced. As4S4 and cisplatin synergistically stimulated p53, phosphor-p38 (p-p38), and increased cleaved caspase 3 (c-caspase 3). Conclusion As4S4 in combination with JQ1, cisplatin, irinotecan or celecoxib showed enhanced cytotoxic effect on gastric and colon cancer cells, indicating the potential application of these novel drug combinations as part of treatment strategy that warrants further investigation. As4S4 and JQ1 demonstrate synergistic activation of p53 and inhibition of c-Myc. As4S4 and cisplatin and celecoxib activated multiple apoptosis pathways.

Efficacy and Safety Profile of Combining Vandetanib with Chemotherapy in Patients with Advanced Non-Small Cell Lung Cancer: A Meta-Analysis

Objective To evaluate the efficacy and safety profile of combining vandetanib with chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). Methods MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ASCO Abstracts, ESMO Abstracts, Wanfang Database, CNKI were searched. Eligible studies were the randomized clinical trials (RCTs) that compared the efficacy and safety profile of adding vandetanib to chemotherapy with single chemotherapy in patients with advanced NSCLC. The outcomes included overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and toxicities. All meta-analysis were performed using Review Manager 5.1. The fixed-effect model weighted by the Mantel-Haenszel method was used. When considerable heterogeneity was found (p<0.1, or I2>50%), further analysis (subgroup analysis, sensitivity analysis or random-effect model) was performed to identify potential cause. Results Results reported from 5 RCTs involving 2284 patients were included in the analysis. Compared to chemotherapy alone, the addition of vandetanib resulted in a significant longer PFS (HR 0.79 [0.72–0.87], p<0.00001) and a higher ORR (RR 1.75 [1.43–2.15], p<0.00001), but failed to show advantage on OS (HR 0.96 [0.87–1.06], p = 0.44). Conclusion Vandetanib has activity in NSCLC. Identification of predictive biomarkers is warranted in future trials to select a subset of patients with advanced NSCLC who may benefit from vandetanib.

Study of Arsenic Sulfide in Solid Tumor Cells Reveals Regulation of Nuclear Factors of Activated T-cells by PML and p53

Arsenic sulfide (AS) has excellent cytotoxic activity in acute promyelocytic leukemia (APL) but its activity in solid tumors remains to be explored. Here we show that AS and cyclosporine A (CsA) exerted synergistic inhibitory effect on cell growth and c-Myc expression in HCT116 cells. AS inhibited the expression of PML, c-Myc, NFATc1, NFATc3, and NFATc4, while stimulating the expression of p53 and NFATc2. Knockdown of PML reduced NFATc1, NFATc2, NFATc3 and NFATc4 expression while overexpression of p53 stimulated NFATc2-luciferase activity that was further augmented by AS by binding to a set of p53 responsive elements (PREs) on the NFATc2 promoter. Additionally, overexpression of p53 suppressed NFATc3 and NFATc4. Reciprocally, NFATc3 knockdown enhanced p53 while reducing MDM2 expression indicating that NFATc3 is a negative regulator of p53 while a positive regulator of MDM2, consistent with its tumor-promoting property as knockdown of NFATc3 retarded cell growth in vitro and tumor growth in xenograft. In patients with colon cancer, tumor expression of NFATc2 correlated with superior survival, while nuclear NFATc1 with inferior survival. These results indicate that AS differentially regulates NFAT pathway through PML and p53 and reveal an intricate reciprocal regulatory relationship between NFAT proteins and p53 pathway.

NFATc3 mediates the sensitivity of gastric cancer cells to arsenic sulfide

Arsenic sulfide (As4S4) is the main component of Realgar which is widely used in traditional Chinese medicine. Previously we showed that As4S4 inhibited the proliferation of colon cancer cells through regulating nuclear factor of activated T cells (NFAT) pathway. Here we explore the role of NFAT in gastric cancer. We showed that As4S4 inhibited the expression of NFATc1, NFATc3, and NFATc4, and modulated the expression of NFATc2 accompanying with p53. The baseline expression of NFATc3 varied distinctly in gastric cancer cell lines (AGS, MGC803, MKN28, MKN45, and SGC7901) and the sensitivity of these cells to As4S4 was dissimilar, with AGS and MGC803 cells showing higher sensitivity while the SGC7901 cells relatively resistant. Interestingly, the sensitivity to As4S4 was correlated with the level of expression of NFATc3, and the cells relatively sensitivity just showing higher expression of NFATc3. Furthermore, NFATc3 expression was significantly higher in gastric cancer tissues compared with the adjacent normal tissues. Our data also showed that, NFATc3 promoted the proliferation of gastric cancer cells by regulating c-Myc. In conclusion, As4S4 inhibited the proliferation of gastric cancer cells through NFATc3/c-Myc pathway and the diverse sensitivity among different cell lines correlated with the expression level of NFATc3 indicating that NFATc3 may be a potential therapeutic target in gastric cancer.Arsenic sulfide (As4S4) is the main component of Realgar which is widely used in traditional Chinese medicine. Previously we showed that As4S4 inhibited the proliferation of colon cancer cells through regulating nuclear factor of activated T cells (NFAT) pathway. Here we explore the role of NFAT in gastric cancer. We showed that As4S4 inhibited the expression of NFATc1, NFATc3, and NFATc4, and modulated the expression of NFATc2 accompanying with p53. The baseline expression of NFATc3 varied distinctly in gastric cancer cell lines (AGS, MGC803, MKN28, MKN45, and SGC7901) and the sensitivity of these cells to As4S4 was dissimilar, with AGS and MGC803 cells showing higher sensitivity while the SGC7901 cells relatively resistant. Interestingly, the sensitivity to As4S4 was correlated with the level of expression of NFATc3, and the cells relatively sensitivity just showing higher expression of NFATc3. Furthermore, NFATc3 expression was significantly higher in gastric cancer tissues compared with the adjacent normal tissues. Our data also showed that, NFATc3 promoted the proliferation of gastric cancer cells by regulating c-Myc. In conclusion, As4S4 inhibited the proliferation of gastric cancer cells through NFATc3/c-Myc pathway and the diverse sensitivity among different cell lines correlated with the expression level of NFATc3 indicating that NFATc3 may be a potential therapeutic target in gastric cancer.

A case report of targeted therapy with apatinib in a patient with advanced gastric cancer and high serum level of alpha-fetoprotein.

Background: Alpha-fetoprotein (AFP) is an important marker for hepatocellular carcinoma, and the detection of serum AFP is currently the principle method for the diagnosis of hepatocellular carcinoma. The prevalence of gastric cancer (GC) with high level of serum AFP is extremely rare, but has unique clinical features. Case summary: We herein present a rare case with GC and high level of serum AFP. A 64-year-old Chinese female underwent gastrectomy was diagnosed as gastric adenocarcinoma and the pathological stage was T1bN0M0, IA. With the progression of disease, the tumor widely metastasized and the serum AFP level increased progressively with the highest level of 3396 ng/mL. She successively entered into 3 lines palliative systematic chemotherapy and fourth-line targeted therapy of apatinib, a small molecule tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor-2. Although previous studies suggested that the prognosis of this special type of GC was poor, this patient lived for 22 months after tumor transfer. Apatinib kept her progression-free survival for 5 months, and the overall survival was 4.5 years. Conclusion: So, we speculate that maybe we can focus apatinib on serum AFP elevated GC patients.