Yen-Yun Wang

Polymorphisms in the apoptosis-associated genes FAS and FASL and risk of oral cancer and malignant potential of oral premalignant lesions in a Taiwanese population.

BACKGROUND Our aim was to measure the relationship of FAS (-1377G>A and -670A>G), FASL (-844C>T) gene variants and risk of oral cancer. METHODS Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to determine the FAS and FASL polymorphisms in 294 oral squamous cell carcinoma (OSCC), 53 oral submucous fibrosis (OSF), and 84 oral leukoplakia (OL) patients, as well as in 333 healthy controls. A standardized questionnaire was applied to collect demographic data, and potential confounding factors. JMP statistical software was used to analyze the association. RESULTS FAS and FASL polymorphisms were not correlated with OSCC development or the malignant potential of OL by simple and multivariate logistic regression. However, a two- to fourfold difference in the risks of betel quid chewing, alcohol consumption, and smoking on OSCC development were observed between participants with different FAS polymorphisms. FAS polymorphisms were significantly correlated with the malignant potential of OSF. Multivariate logistic regression analysis indicated that FAS A(-1377)-G(-670) vs. G(-1377)-A(-670) haplotype (OR = 2.26, 95% CI = 1.16-4.41) was correlated with the malignant potential of OSF. CONCLUSIONS We suggest that FAS and FASL polymorphisms are not significantly correlated with OSCC development or malignant potential of OL. The impact of substance usage on OSCC development could be differentiated by FAS polymorphisms. FAS A(-1377)-G(-670) haplotype may play a role in the malignant potential of OSF.

Associations of diet with body burden of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) : Observations on pregnant women from central Taiwan

The aim of this study was to examine the relationship between placental polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCBs) toxic equivalent (TEQ) levels and the consumption of various food types in pregnant women from central Taiwan. Placental PCDD/Fs and PCB congener TEQ levels were evaluated in 109 pregnant women and dietary information was obtained by questionnaire. TEQ levels of PCDD/Fs and PCBs were positively associated with age and annual family incomes (p < 0.05). PCDD/F TEQs were significantly associated with freshwater fish and dairy product consumption after adjustment for age and body mass index (BMI) (p < 0.05). For PCB TEQs, significant associations were detected for saltwater fish consumption (p < 0.05). In summary, positive correlations were found between freshwater fish and dairy product intake and PCDD/F levels, and a marginal correlation between saltwater fish intake and the body burden of PCBs in pregnant women from central Taiwan. Risk assessment of PCDD/Fs and PCB in fishery products is warranted in a future study to quantify the benefits of fish consumption during the perinatal period.

Molecular characterization of oral squamous cell carcinoma using targeted next-generation sequencing

OBJECTIVES Many genetic factors play an important role in the development of oral squamous cell carcinoma. The aim of this study was to assess the mutational profile in oral squamous cell carcinoma using formalin-fixed, paraffin-embedded tumors from a Taiwanese population by performing targeted sequencing of 26 cancer-associated genes that are frequently mutated in solid tumors. METHODS Next-generation sequencing was performed in 50 formalin-fixed, paraffin-embedded tumor specimens obtained from patients with oral squamous cell carcinoma. Genetic alterations in the 26 cancer-associated genes were detected using a deep sequencing (>1000X) approach. RESULTS TP53, PIK3CA, MET, APC, CDH1, and FBXW7 were most frequently mutated genes. Most remarkably, TP53 mutations and PIK3CA mutations, which accounted for 68% and 18% of tumors, respectively, were more prevalent in a Taiwanese population. Other genes including MET (4%), APC (4%), CDH1 (2%), and FBXW7 (2%) were identified in our population. CONCLUSIONS In summary, our study shows the feasibility of performing targeted sequencing using formalin-fixed, paraffin-embedded samples. Additionally, this study also reports the mutational landscape of oral squamous cell carcinoma in the Taiwanese population. We believe that this study will shed new light on fundamental aspects in understanding the molecular pathogenesis of oral squamous cell carcinoma and may aid in the development of new targeted therapies.

The Synthetic β-Nitrostyrene Derivative CYT-Rx20 Inhibits Esophageal Tumor Growth and Metastasis via PI3K/AKT and STAT3 Pathways

The β-nitrostyrene family have been implicated for anti-cancer property. However, the pharmacological role of β-nitrostyrene in esophageal cancer remain unclear. Here, a β-nitrostyrene derivative, CYT-Rx20, was synthesized and assessed for its anti-cancer activities and underlying mechanism in esophageal cancer. CYT-Rx20 induced cytotoxicity in esophageal cancer cells by promoting apoptosis through activation of caspase cascade and poly(ADP-ribose) polymerase (PARP) cleavage. Besides, CYT-Rx20 inhibited esophageal cancer cell migration and invasion by regulating the expression of epithelial to mesenchymal transition (EMT) markers. CYT-Rx20 decreased cell viability and migration through suppression of the PI3K/AKT and STAT3 pathways. Of note, the cytotoxicity and anti-migratory effect of CYT-Rx20 were enhanced by co-treatment with SC79 (AKT activator) or colivelin (STAT3 activator), suggesting the dependency of esophageal cancer cells on AKT and STAT3 for survival and migration, an oncogene addiction phenomenon. In xenograft tumor-bearing mice, CYT-Rx20 significantly reduced tumor growth of the implanted esophageal cancer cells accompanied by decreased Ki-67, phospho-AKT, and phospho-STAT3 expression. In orthotopic esophageal cancer mouse model, decreased tumor growth and lung metastasis with reduced Ki-67 and phospho-STAT3 expression were observed in mice treated with CYT-Rx20. Together, our results suggest that CYT-Rx20 is a potential β-nitrostyrene-based anticancer compound against the tumor growth and metastasis of esophageal cancer.

Plasma polyunsaturated fatty acids and periodontal recovery in Taiwanese with periodontitis: A significant relationship

BACKGROUND Plasma levels of polyunsaturated fatty acids (PUFAs) are different before and after periodontal treatment. Asians and Westerners have significantly different baseline levels of plasma PUFAs. However, no Asian study has reported the effects of nonsurgical treatment on the correlation between periodontal condition and plasma levels of PUFAs. We analyzed whether recovery from periodontitis was correlated with the elevation of plasma fatty acids 3 months after the nonsurgical intervention and with no recommended supplements. DESIGN Thirty-five Taiwanese patients with periodontitis were recruited. Probing pocket depths (PPDs) and clinical attachment levels (CALs) were measured at baseline and 3 months after the nonsurgical treatment. Plasma levels of fatty acids were determined using gas chromatography. Differences and correlations between plasma fatty acid composition and periodontitis severity at baseline and 3 months after treatment were determined. RESULTS Twenty-six patients completed the study. At the baseline, PPDs were negatively correlated with plasma n-3 PUFAs (r=-0.52, p<0.01), but at 3 months post intervention, periodontitis severity had declined and the weight percentages of n-3 PUFAs, DPA, and DHA were significantly (p=0.019, 0.005, and 0.037, respectively) higher. The recovery percentages of CALs were positively and significantly correlated with plasma ΔPUFAs and the percentage of Δn-3 PUFAs in ΔPUFAs (r=0.42 and 0.45, respectively; p<0.05 for both). CONCLUSIONS We conclude that a higher weight percentage of n-3 PUFAs in total PUFAs was related to the recovery of CALs 3 months after the nonsurgical periodontal treatment. However, no such relationship was found for PPDs.

3′-Hydroxy-4′-methoxy-β-methyl-β-nitrostyrene inhibits tumor growth through ROS generation and GSH depletion in lung cancer cells

Aims: Members of the &bgr;‐nitrostyrene family are known to suppress tumor growth, with the underlying mechanisms of &bgr;‐nitrostyrene remain mostly unclear. Herein, we synthesized a &bgr;‐nitrostyrene derivative, 3′‐hydroxy‐4′‐methoxy‐&bgr;‐methyl‐&bgr;‐nitrostyrene (CYT‐Rx20), and explored its anticancer activities in human lung cancer cells in vitro and in vivo. Main methods: Cell viability was measured by XTT assay. Apoptosis was detected by Annexin V/PI staining. Caspase activation was determined by western blotting. ROS (reactive oxygen species), MMP (mitochondrial membrane potential) and mitochondrial mass were determined by flow cytometry. GSH level was detected by ELISA assay. Key findings: In this study, we found that CYT‐Rx20 significantly reduced cell viability, accompanied by G2/M arrest in lung cancer cells. Increased protein levels of cleaved‐caspase families indicated apoptotic cell death upon CYT‐Rx20 treatment. Furthermore, increased level of intracellular reactive oxygen species (ROS), loss of mitochondrial membrane potential (&Dgr;&PSgr;m), glutathione (GSH) depletion and inhibition of GSH reductase were observed after CYT‐Rx20 treatment. The effects of CYT‐Rx20 on cell viability and the loss of &Dgr;&PSgr;m were significantly reversed when cells were pretreated with thiol antioxidants NAC, GSH, or 2‐ME. Finally, xenograft animal study demonstrated that CYT‐Rx20 significantly suppressed lung tumor growth in vivo. Significance: Our data demonstrated that CYT‐Rx20 triggered apoptotic cell death in lung cancer cells and suppressed lung tumor growth through GSH depletion, suggesting that CYT‐Rx20 may have the potential to be further developed as an anticancer compound for treating lung cancer.

CYT-Rx20 inhibits ovarian cancer cells in vitro and in vivo through oxidative stress-induced DNA damage and cell apoptosis

AbstractPurpose The β-nitrostyrene family has been previously reported to possess anticancer property. However, the biological effects of β-nitrostyrenes on ovarian cancer and the underlying mechanisms involved remain unclear. In the present study, we synthesized a β-nitrostyrene derivative, CYT-Rx20 3′-hydroxy-4′-methoxy-β-methyl-β-nitrostyrene), and investigated its anticancer effects and the putative pathways of action in ovarian cancer.Methods The effects of CYT-Rx20 were analyzed using cell viability assay, reactive oxygen species (ROS) generation assay, FACS analysis, annexin V staining, immunostaining, comet assay, immunoblotting, soft agar assay, migration assay, nude mice xenograft study and immunohistochemistry.ResultsCYT-Rx20 induced cytotoxicity in ovarian cancer cells by promoting cell apoptosis via ROS generation and DNA damage. CYT-Rx20-induced cell apoptosis, ROS generation and DNA damage were reversed by thiol antioxidants. In addition, CYT-Rx20 inhibited ovarian cancer cell migration by regulating the expression of epithelial to mesenchymal transition (EMT) markers. In nude mice, CYT-Rx20 inhibited ovarian tumor growth accompanied by increased expression of DNA damage marker γH2AX and decreased expression of EMT marker Vimentin.ConclusionsCYT-Rx20 inhibits ovarian cancer cells in vitro and in vivo, and has the potential to be further developed into an anti-ovarian cancer drug clinically.

Differential resistance to platinum-based drugs and 5-fluorouracil in p22phox-overexpressing oral squamous cell carcinoma: Implications of alternative treatment strategies

We have previously shown that p22phox confers resistance to cisplatin in oral squamous cell carcinoma (OSCC). Whether p22phox has clinical correlation with cisplatin resistance and affects the efficacy of other platinum or nonplatinum drugs is unknown.

Overexpression of sprouty2 in human oral squamous cell carcinogenesis

OBJECTIVE This study investigated SPRY2 expression in human oral potentially malignant disorders (OPMDs) and oral squamous cell carcinomas (OSCCs). METHODS 75 OSCCs, 23 OPMDs with malignant transformation (MT), 17 OPMDs without MT, and eight normal oral mucosa (NOM) tissues were used for immunohistochemical staining; three OSCC tissues with normal tissue counterparts were used for western blotting. Three human oral cancer cell lines (OCCLs), an oral precancer cell line (DOK), and a NOM primary culture (NOMPC) were used for western blotting; OCCLs and NOMPC were employed for real-time quantitative reverse transcription-polymerase chain reaction. OCCLs were evaluated in terms of proliferation, migration, invasion and BRAF V600E point mutation assays. RESULTS Significantly increased SPRY2 protein expression was observed in OSCCs as compared with NOM, and SPRY2 expression also differed between OSCC patients with and without lymph-node metastasis. SPRY2 protein and mRNA expressions were significantly enhanced as compared with NOMPC. Increased phospho-ERK expression was observed in OCCLs as compared with NOMPC. Significant decreases in the proliferation rate, degrees of migration and invasion were noted in OCCLs with SPRY2 siRNA transfection as compared with those without SPRY2 siRNA transfection. No BRAF V600E point mutation was observed for OCCLs as compared with NOMPC. A significantly increased SPRY2 protein level was noted in OPMDs with MT as compared to those without MT, and was also found in OPMDs with MT in comparison with NOM, as well as in DOK in comparison with NOMPC. CONCLUSIONS Our results indicated that SPRY2 overexpression is associated with human oral squamous-cell carcinogenesis.

Cyt-rx20 Inhibits Cervical Cancer Cell Growth and Migration Through Oxidative Stress-induced Dna Damage, Cell Apoptosis, and Epithelial-to-mesenchymal Transition Inhibition

Objective The β-nitrostyrene family has been reported to possess anticancer properties. However, the anticancer activity of β-nitrostyrenes on cervical cancer cells and the underlying mechanisms involved remain unexplored. In this study, a β-nitrostyrene derivative CYT-Rx20 (3′-hydroxy-4′-methoxy-β-methyl-β-nitrostyrene) was synthesized, and its anticancer activity on cervical cancer cells and the mechanisms involved were investigated. Methods The effect of CYT-Rx20 on human cervical cancer cell growth was evaluated using cell viability assay. Reactive oxygen species (ROS) generation and annexin V staining were detected by flow cytometry. The protein expression levels of cleaved caspase-3, cleaved caspase-9, cleaved poly (ADPribose) polymerase, γH2AX, β-catenin, Vimentin, and Twist were measured by Western blotting. DNA double-strand breaks were determined by γ-H2AX foci formation and neutral comet assay. Migration assay was used to determine cancer cell migration. Nude mice xenograft was used to investigate the antitumor effects of CYT-Rx20 in vivo. Results CYT-Rx20 induced cytotoxicity in cervical cancer cells by promoting cell apoptosis via ROS generation and DNA damage. CYT-Rx20-induced cell apoptosis, ROS generation, and DNA damage were reversed by thiol antioxidants. In addition, CYT-Rx20 inhibited cervical cancer cell migration by regulating the expression of epithelial-to-mesenchymal transition markers. In nude mice, CYT-Rx20 inhibited cervical tumor growth accompanied by increased expression of DNA damage marker γH2AX and decreased expression of mesenchymal markers β-catenin and Twist. Conclusions CYT-Rx20 inhibits cervical cancer cells in vitro and in vivo and has the potential to be further developed into an anti-cervical cancer drug clinically.