Tetrandrine Enhances H2O2-Induced Apoptotic Cell Death Through Caspase-dependent Pathway in Human Keratinocytes

BACKGROUND

Tetrandrine, a bis-benzylisoquinoline alkaloid, induces apoptosis of many types of human cancer cell. Hydrogen peroxide (H₂O₂) is a reactive oxygen species inducer; however, there are no reports to show whether pre-treatment of tetrandrine with H₂O₂ induces more cell apoptosis than H₂O₂ alone. Thus, the present study investigated the effects of tetrandrine on H₂O₂-induced cell apoptosis of human keratinocytes, HaCaT, in vitro.

MATERIALS AND METHODS

HaCaT cells were pre-treated with and without tetrandrine for 1 h, and then treated with H₂O₂ for examining cell morphological changes and cell viability using contrast-phase microscopy and propidium iodide (PI) exclusion assay, respectively. Cells were measured apoptotic cell death by using annexin V/PI double staining and further analyzed by flow cytometer. Cells were further assessed for DNA condensation using 2-(4-amidinophenyl)-6-indolecarbamidine staining. Western blotting was used to measure expression of apoptosis-associated proteins and confocal laser microscopy was used to measure the protein expression and nuclear translocation from the cytoplasm to nuclei.

RESULTS

Pre-treatment of tetrandrine for 1 h and treatment with H₂O₂ enhanced H₂O₂-induced cell morphological changes and reduced cell viability, whilst increasing apoptotic cell death and DNA condensation. Furthermore, tetrandrine significantly increased expression of reactive oxygen species-associated proteins such as superoxide dismutase (Cu/Zn) and superoxide dismutase (Mn) but significantly reduced the level of catalase, which was also confirmed by confocal laser microscopy. It also increased expression of DNA repair-associated proteins ataxia telangiectasia mutated, ataxia-telangectasia and Rad3-related, phospho-P53, P53 and phosphorylated histone H2AX, and of pro-apoptotic proteins BCL2 apoptosis regulator-associated X-protein, caspase-3, caspase-8, caspase-9 and poly ADP ribose polymerase in HaCaT cells.

CONCLUSION

These are the first and novel findings showing tetrandrine enhances H₂O₂-induced apoptotic cell death of HaCaT cells and may provide a potent approach for the treatment of proliferated malignant keratinocytes.

Pre-Treatment of Pterostilbene Enhances H2O2-induced Cell Apoptosis Through Caspase-dependent Pathway in Human Keratinocyte Cells

BACKGROUND/AIM

Hydrogen peroxide (H₂O₂) is one of the reactive oxygen species (ROS), which can induce apoptotic cell death in numerous cancer cells. Pterostilbene (PTE), a natural polyphenolic compound, induces cell apoptosis in many human cancer cells.

MATERIALS AND METHODS

We investigated whether PTE could enhance H₂O₂-induced cell apoptosis in human keratinocyte HaCaT cells in vitro. The morphological change of HaCaT cells was observed and photographed under a contrast-phase microscope. The percentage of cell viability was measured by propidium iodide exclusion assay. Cell apoptosis was performed by Annexin V/PI double staining and assayed by flow cytometer. DNA condensation was measured by DAPI staining. The protein expression was determined by western blotting. ROS production-associated proteins were also assayed by confocal laser scanning microscopy.

RESULTS

PTE pre-treatment enhanced H₂O₂ (600 μM)-induced cell morphological changes and reduced the total cell number (cell viability). The decreased cell viability in HaCaT cells was through induction of apoptotic cell death, which was confirmed by Annexin V/PI double staining and DAPI staining. Western blotting studies indicated that HaCaT cells which were pre-treated with PTE (100 μM) and then co-treated with H₂O₂ (600 μM) for 12 h showed significantly increased levels of SOD (Cu/Zn), SOD (Mn), Bax, caspase-3, caspase-8, caspase-9, PARP, p53, p-p53, and p-H2A.X but decreased levels Bcl-2 and catalase. Results also showed that HaCaT cells pre-treated with PTE and then co-treated with H₂O₂ had increased expression of SOD (Cu/Zn) and glutathione but decreased catalase.

CONCLUSION

These observations suggest that PTE pre-treatment can enhance the H₂O₂-induced apoptotic cell death in keratinocyte cells and may be an effective candidate for the treatment of proliferative keratinocytes.

Citronellol Induces Necroptosis of Human Lung Cancer Cells via TNF-α Pathway and Reactive Oxygen Species Accumulation

BACKGROUND/AIM

Our current study aimed to determine the molecular mechanisms of citronellol-induced cell death and ROS accumulation in non-small cell lung cancer (NCI-H1299 cells) and also compare the anticancer effects of citronellol and EOPC.

MATERIALS AND METHODS

ROS measurement and western blotting were performed to detect whether citronellol can induce necroptosis in vitro. Besides, we performed an in vivo analysis of tumourigenesis inhibition by citronellol treatment in BALB/c (nu/nu) nude mice.

RESULTS

Necroptosis occured by up-regulating TNF-α, RIP1/RIP3 activities, and down-regulating caspase-3/caspase-8 activities after citronellol treatment in NCI-H1299 cells. Citronellol also resulted in a biphasic increase in ROS production at 1 h and at 12 h in NCI-H1299 cells. Xenograft model experiments showed that citronellol could effectively inhibit subcutaneous tumours produced 4 weeks after intraperitoneal injection of NCI-H1299 in BALB/c nude mice.

CONCLUSION

Citronellol induced necroptosis of NCI-H1299 cells via TNF-α pathway and ROS accumulation.

Banana Flower Extract Suppresses Benign Prostatic Hyperplasia by Regulating the Inflammatory Response and Inducing G1 Cell-cycle Arrest

BACKGROUND/AIM

The banana flower is used for ameliorating urinary disturbance. However, there is limited evidence to support the efficacy or mechanism of action of banana flower against benign prostatic hyperplasia (BPH). In the present study, the anti-BPH activity and mechanisms of banana flower extracts were investigated in vitro and in vivo.

MATERIALS AND METHODS

The banana flower extract is a water-soluble extract obtained by sonication. MTT assay was used to examine whether banana flower extract exhibited cytotoxic effects on BPH-1 cells. The effect of banana flower extract on cell-cycle distribution was examined by flow cytometry. The expression of cell-cycle-regulatory molecules was determined by western blot analysis. Testosterone propionate (TP)-induced rat model of BPH was used to evaluate the anti-BPH activity of banana flower extract in vivo.

RESULTS

Banana flower extract reduced epithelial cell line BPH-1 cell viability through cell-cycle arrest at G₁ phase. Moreover, banana flower extract reduced the expression of cyclin D1 and cyclin-dependent kinase 6, while it increased the expression of p53 and p27. Interestingly, banana flower extract suppressed BPH-related inflammatory responses through suppressing cyclo-oxygenase-2 expression and prostaglandin E2 production. Finally, banana flower extract administered orally to male rats reduced prostatic weight and serum dihydrotestosterone level, and improved prostate gland morphology. High-performance liquid chromatography revealed that banana flower extract contains citric acid, taurine, pantothenic acid and nicotinic acid components. In summary, banana flower extract may be used as a therapeutic agent for BPH via anti-proliferative and anti-inflammatory activities.

The Association of Matrix Metalloproteinase-1 Promoter Polymorphisms with Breast Cancer

BACKGROUND/AIM

The family of matrix metalloproteinases (MMPs) are responsible for the homeostasis of extracellular matrix components and their genetic polymorphisms may be associated with cancer susceptibility. The serum levels of MMP-1 have been reported to be lower in breast cancer patients than healthy subjects. In the current study, we aimed at investigating the contribution of a polymorphism in the promoter region of MMP-1 to breast cancer in Taiwan.

MATERIALS AND METHODS

The MMP-1 rs1799705 polymorphic genotypes were genotyped among 1,232 breast cancer patients and 1,232 healthy controls by the typical polymerase chain reaction-restriction fragment length polymorphism methodology.

RESULTS

The percentages of 2G/2G, 1G/2G, and 1G/1G for MMP1 -1607 genotypes were 35.4, 40.6 and 24.0% in the breast cancer group and 34.1, 43.6, and 22.3% in the healthy control group (p trend=0.3025), respectively. The odds ratios (ORs) after adjusting for age, smoking and alcohol drinking status for those carrying 1G/2G and 1G/1G genotypes at MMP1 -1607 were 0.93 (95%CI=0.76-1.11, p=0.2390) and 1.01 (95%CI=0.77-1.23, p=0.7377), respectively, compared to those carrying the wild-type 2G/2G genotype. Supporting this finding, the adjusted OR for those carrying the 1G allele at MMP-1 -1607 was 1.03 (95%CI=0.91-1.18, p=0.8860), compared to those carrying the wild-type 2G allele. Our findings suggest that the polymorphic genotypes at MMP1 promoter -1607 investigated in the current study, may not play a major role in determining cancer susceptibility to breast cancer in Taiwan. Other early diagnostic and predictive markers are urgently needed for personalized and precise breast cancer detection and therapy.

2-Phenylnaphthyridin-4-one Derivative LYF-11 Inhibits Interleukin-6-mediated Epithelial-to-Mesenchymal Transition via the Inhibition of JAK2/STAT3 Signaling Pathway in MCF-7 Cells

BACKGROUND/AIM

Breast tumor interleukin-6 (IL-6) level increases with tumor grade, and elevated serum IL-6 correlates with poor survival in patients with breast cancer. Epithelial-mesenchymal transition (EMT) phenotypes are associated with enhanced metastasis and unfavorable clinical outcome in breast cancer. Therefore, we examined whether IL-6 induced EMT phenotype characterized in breast cancer cells.

MATERIALS AND METHODS

MCF-7 cells treated with different concentrations (10-50 ng/ml) of IL-6 for 24 and 48 h. Western blotting, flow cytometry, and cell migration assay were used to test whether IL-6 promoted tumor-initiating ability in MCF-7 cells.

RESULTS

In this study, we found that the induction of EMT by IL-6 resulted in the acquisition of mesenchymal traits and the increase of tumor-initiating ability in MCF-7 cells. Moreover, we found that 2-phenylnaphthy-ridin-4-one derivatives were able to repress IL-6 induced EMT phenotype and tumor-initiating ability. Among these deriveratives, LYF-11 possessed the most potential inhibitory activity. LYF-11 effectively inhibited IL-6-induced EMT phenotype and tumor-initiating ability via the inhibition of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway.

CONCLUSION

Our results suggest a connection between IL-6 receptor activity and EMT phenotype, and tumor-initiating ability. Moreover, LYF-11 is a potential compound for breast cancer therapy by targeting JAK2/STAT3 signaling pathway.

The Association of Matrix Metalloproteinase-8 Promoter Genotypes in Breast Cancer

BACKGROUND/AIM

The family of matrix metalloproteinases (MMPs) controls homeostasis of the extracellular matrix and their genetic polymorphisms may be associated with personal cancer susceptibility. The serum levels of MMP8 was reported to be higher in patients with breast cancer than in healthy individuals. In this study, we aimed to investigate the contribution of a polymorphism in the promoter region of MMP8 (-799C/T) and two nonsynonymous polymorphisms (Val436Ala and Lys460Thr) to breast cancer.

MATERIALS AND METHODS

MMP8 -799C/T, Val436Ala and Lys460Thr polymorphic genotypes were determined for 1,232 patients with breast cancer and 1,232 healthy controls by polymerase chain reaction-restriction fragment length polymorphism methodology.

RESULTS

The odds ratios (ORs) after adjusting for age, gender, smoking and alcohol drinking status for those carrying CT and TT genotypes at the MMP8 promoter C-799T were 1.03 (95% CI=0.88-1.23, p=0.7475) and 1.08 (95% CI=0.91-1.53, p=0.3561), respectively, compared to those carrying the wild-type CC genotype. The OR for the combined T-bearing genotypes were of a similar non-significant level (OR=1.05, 95% CI=0.90-1.26, p=0.5176). Supporting this finding, the adjusted OR for those carrying the T allele at MMP8 C-799T was 1.05 (95% CI=0.86-1.21, p=0.3797), compared to those carrying the wild-type C allele. There was also no significant association of MMP8 Lys460Thr with breast cancer. There was no polymorphic genotype at MMP8 Val436Ala found among any of the investigated individuals.

CONCLUSION

MMP8 -799C/T, Val436Ala and Lys460Thr polymorphisms may only play an indirect role in determining personal cancer susceptibility to breast cancer in Taiwan.

The Contribution of Matrix Metalloproteinase-7 Promoter Genotypes in Breast Cancer in Taiwan

BACKGROUND/AIM

The matrix metalloproteinase (MMP) family of enzymes are in charge of degradation of various components of the extracellular matrix and their functional genetic polymorphisms may be associated with cancer susceptibility. The functional polymorphisms in the promoter region of MMP7 (A-181G and C-153T) have been reported to influence the binding capacity of nuclear proteins and may contribute to genetic susceptibility to cancer. In this study, we focused on investigating the contribution of the genotypes of MMP7 (A-181G and C-153T) to breast cancer in Taiwan.

MATERIALS AND METHODS

These two polymorphisms were genotyped in 1,232 patients with breast cancer and 1,232 controls by polymerase chain reaction-restriction fragment length polymorphism methodology.

RESULTS

The odds ratios (ORs) after adjusting for age, family history of cancer, smoking and alcohol drinking status for those carrying AG and GG genotypes at MMP7 promoter A-181G were 1.22 (95%CI=0.91-1.63, p=0.2235) and 2.84 (95%CI=1.64-7.48, p=0.0007) respectively, compared to those carrying the wild-type AA genotype. Supporting this finding, the adjusted OR for those carrying the G allele at MMP7 promoter A-181G was 1.57 (95%CI=1.29-1.93, p=0.0008), compared to those carrying the wild-type A allele. There was no polymorphic genotype at MMP7 C-153T found among any of the investigated individuals.

CONCLUSION

Our findings suggest that the MMP7 A-181G polymorphisms may play a role in determining personal cancer susceptibility and GG genotype at MMP7 A-181G may serve as a biomarker for early detection and prediction of breast cancer in Taiwanese.

Large-scale mitochondrial DNA deletions in weak goslings

1. Evidence has accumulated in mammals to support the idea that mitochondrial DNA (mtDNA) deletions and mutations might contribute to ageing and reproductive failure. White Roman geese were monitored to evaluate the effect of large-scale deletions of mtDNA in an avian species. 2. A total of 340 samples from 114 dead embryos, 111 weak goslings, and 115 normal goslings were used in this experiment. The regions of these two large-scale mtDNA deletions, ΔmtDNA6829 and ΔmtDNA6992, were between the COI and ND5 genes. A 3·6% (4 out of 111) positive sample was detected in the weak goslings. In contrast, no large-scale mitochondrial DNA deletions were detected in either the dead embryos (0 out of 114) or the normal goslings (0 out of 115). 3. Large-scale mtDNA deletions may be a factor causing weak goslings.

The origin of the white Roman goose

In order to avoid interference from nuclear copies of mitochondrial DNA (numts), mtDNA of the white Roman goose (domestic goose) was extracted from liver mitochondria. The mtDNA control region was amplified using a long PCR strategy and then sequenced. Neighbor-joining, maximum parsimony, and maximum-likelihood approaches were implemented using the 1,177 bp mtDNA control region sequences to compute the phylogenetic relationships of the domestic goose with other geese. The resulting identity values for the white Roman geese were 99.1% (1,166/1,177) with western graylag geese and 98.8% (1,163/1,177) with eastern graylag geese. In molecular phylogenetic trees, the white Roman goose was grouped in the graylag lineage, indicating that the white Roman goose came from the graylag goose (Anser anser). Thus, the scientific name of the white Roman goose should be Anser anser 'White Roman.'