Expression analysis and biological regulation of silencing regulatory protein 6 (SIRT6) in cutaneous squamous cell carcinoma

Abstract Background Cutaneous squamous cell carcinoma (CSCC) is one of the most common types of skin cancer worldwide. Therefore, the identification of biomarkers associated with CSCC progression could aid in the early detection of high-risk squamous cell carcinoma and the development of novel therapeutic strategies. Objective This study aimed to investigate the expression patterns of silent mating type Information Regulation 2 homolog 6 (SIRT6) in CSCC and its clinical significance. Methods The protein expression level of SIRT6 in tissues was detected by immunohistochemistry, and the correlation between SIRT6 expression and clinicopathological parameters in CSCC patients was analyzed. The relative expression of SIRT6 in CSCC cell lineage and tissue specimens was determined by western blotting and PCR. The effect of SIRT6 silencing on cell proliferation was evaluated using cell counting kit 8. Wound healing, transwell method, and flow cytometry were used to investigate the migration, invasion, and cell cycle distribution/apoptosis of CSCC cells after SIRT6 silencing, respectively. Western blot was used to detect the expression of EMT (Epithelial-Mesenchymal Transition), cycle, apoptosis, and other related proteins. Results The high expression of SIRT6 was correlated with the location of cancer tissue and Broder staging in CSCC patients. Knockdown of SIRT6 inhibited the proliferation, migration, invasion and EMT of CSCC cells, and promoted their apoptosis, with cells blocked in G1 phase. Study limitations No animal experiments were conducted to further verify the results. Conclusion Decreased expression of SIRT6 can inhibit the occurrence and development of CSCC.

Expression analysis and biological regulation of silencing regulatory protein 6 (SIRT6) in cutaneous squamous cell carcinoma.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is one of the most common types of skin cancer worldwide. Therefore, the identification of biomarkers associated with CSCC progression could aid in the early detection of high-risk squamous cell carcinoma and the development of novel therapeutic strategies. OBJECTIVE: This study aimed to investigate the expression patterns of silent mating type Information Regulation 2 homolog 6 (SIRT6) in CSCC and its clinical significance. METHODS: The protein expression level of SIRT6 in tissues was detected by immunohistochemistry, and the correlation between SIRT6 expression and clinicopathological parameters in CSCC patients was analyzed. The relative expression of SIRT6 in CSCC cell lineage and tissue specimens was determined by western blotting and PCR. The effect of SIRT6 silencing on cell proliferation was evaluated using cell counting kit 8. Wound healing, transwell method, and flow cytometry were used to investigate the migration, invasion, and cell cycle distribution/apoptosis of CSCC cells after SIRT6 silencing, respectively. Western blot was used to detect the expression of EMT (Epithelial-Mesenchymal Transition), cycle, apoptosis, and other related proteins. RESULTS: The high expression of SIRT6 was correlated with the location of cancer tissue and Broder staging in CSCC patients. Knockdown of SIRT6 inhibited the proliferation, migration, invasion and EMT of CSCC cells, and promoted their apoptosis, with cells blocked in G1 phase. STUDY LIMITATIONS: No animal experiments were conducted to further verify the results. CONCLUSION: Decreased expression of SIRT6 can inhibit the occurrence and development of CSCC.

Doublecortin-like kinase 2 promotes breast cancer cell invasion and metastasis.

BACKGROUND: Doublecortin-like kinase 2 (DCLK2) is a microtubule-associated protein kinase that participates in neural development and maturation; however, whether it is involved in tumour progression remains unclear. METHODS: DCLK2 overexpression and knockdown clones were established by lentivirus transfection. Western blot, PCR assays and bioinformatics analyses were conducted to observe the expression of DCLK2. CCK8, colony formation, scratch migration and Transwell assays were used to detect cell proliferation, migration and invasion, respectively. Tumour metastasis was evaluated in vivo using a tail vein metastasis model. Bioinformatics analyses were performed to analyse the expression correlation between DCLK2 and TCF4, or EMT markers in breast cancer. RESULTS: Our data indicate that DCLK2 is highly expressed in breast cancer cells and is associated with poor prognosis. Silencing DCLK2 does not affect the proliferation rate of tumour cells, but significantly suppresses migration and invasion as well as lung metastasis processes. Overexpression of DCLK2 can enhance the migratory and invasive abilities of normal breast epithelial cells. Moreover, TCF4/ß-catenin inhibitor LF3 downregulates the expression of DCLK2 and inhibits the migration and invasion of breast cancer cells. Furthermore, we found that the downregulation of DCLK2 blocks the epithelial-mesenchymal transition (EMT) process. CONCLUSION: Our study indicates that DCLK2 plays an important role in EMT, cell invasion and metastasis, suggesting that DCLK2 is a potential target for the treatment of metastatic breast cancer.

Synthetic antimicrobial agents inhibit aflatoxin production.

Antimicrobial peptides (AMPs) are biologically active molecules that can eradicate bacteria by destroying the bacterial membrane structure, causing the bacteria to rupture. However, little is known about the extent and effect of AMPs on filamentous fungi. In this study, we synthesized small molecular polypeptides by an inexpensive heat conjugation approach and examined their effects on the growth of Aspergillus flavus and its secondary metabolism. The antimicrobial agents significantly inhibited aflatoxin production, conidiation, and sclerotia formation in A. flavus. Furthermore, we found that the expression of aflatoxin structural genes was significantly inhibited, and the intracellular reactive oxygen species (ROS) level was reduced. Additionally, the antimicrobial agents can change membrane permeability. Overall, our results demonstrated that antimicrobial agents, safe to mammalian cells, have an obvious impact on aflatoxin production, which indicated that antimicrobial agents may be adopted as a new generation of potential agents for controlling aflatoxin contamination.

Consequences of Phenytoin Exposure on Hepatic Cytochrome P450 Expression during Postnatal Liver Maturation in Mice.

The induction of cytochrome P450 (P450) enzymes in response to drug treatment is a significant contributing factor to drug-drug interactions, which may reduce therapeutic efficacy and/or cause toxicity. Since most studies on P450 induction are performed in adults, enzyme induction at neonatal, infant, and adolescent ages is not well understood. Previous work defined the postnatal ontogeny of drug-metabolizing P450s in human and mouse livers; however, there are limited data on the ontogeny of the induction potential of each enzyme in response to drug treatment. Induction of P450s at the neonatal age may also cause permanent alterations in P450 expression in adults. The goal of this study was to investigate the short- and long-term effects of phenytoin treatment on mRNA and protein expressions and enzyme activities of CYP2B10, 2C29, 3A11, and 3A16 at different ages during postnatal liver maturation in mice. Induction of mRNA immediately following phenytoin treatment appeared to depend on basal expression of the enzyme at a specific age. While neonatal mice showed the greatest fold changes in CYP2B10, 2C29, and 3A11 mRNA expression following treatment, the levels of induced protein expression and enzymatic activity were much lower than that of induced levels in adults. The expression of fetal CYP3A16 was repressed by phenytoin treatment. Neonatal treatment with phenytoin did not permanently induce enzyme expression in adulthood. Taken together, our data suggest that inducibility of drug-metabolizing P450s is much lower in neonatal mice than it is in adults and neonatal induction by phenytoin is not permanent.

Relationship Between the Anxious Symptoms and the Neurotransmitter in Parkinson's Mice with Different Dosages of MPTP

ABSTRACT This study aims to explore the relationship between the anxious symptoms and the impairment of 5-hydroxytryptamine system in PD mice induced by different dosages of MPTP. The mice from the three model groups, the low-dose, dose and high-dose group, took longer time in the dark box than those in the control group (P<0.05). However, no statistically significant differences were found among the model groups. The number of open arm entry (OE) and the open arm time (OT) were significant lower in the model group than those in the control group in the elevated plus-maze test (P＜0.05). The percentage of OE in modle group was significantly lower compared with the control group (P＜0.05). The concentrations of striatum DA, HVA, 5-HT, and 5-HIAA were significantly reduced in the three model groups compared to the control group (P＜0.05). The 5-HT concentrations of high-dose group was significantly lower than those of the control group in the prefrontal cortex (P＜0.05). Anxiety symptoms were appeared in the three model groups of early PD mice, but no difference existed among these groups. The 5-hydroxytryptamine system was damaged after MPTP injection, which could lead to anxiety. However, the impairment of 5-hydroxytryptamine system induced by MPTP was dose-independent.

Identification of candidate genes for lung cancer somatic mutation test kits.

Over the past three decades, mortality from lung cancer has sharply and continuously increased in China, ascending to the first cause of death among all types of cancer. The ability to identify the actual sequence of gene mutations may help doctors determine which mutations lead to precancerous lesions and which produce invasive carcinomas, especially using next-generation sequencing (NGS) technology. In this study, we analyzed the latest lung cancer data in the COSMIC database, in order to find genomic "hotspots" that are frequently mutated in human lung cancer genomes. The results revealed that the most frequently mutated lung cancer genes are EGFR, KRAS and TP53. In recent years, EGFR and KRAS lung cancer test kits have been utilized for detecting lung cancer patients, but they presented many disadvantages, as they proved to be of low sensitivity, labor-intensive and time-consuming. In this study, we constructed a more complete catalogue of lung cancer mutation events including 145 mutated genes. With the genes of this list it may be feasible to develop a NGS kit for lung cancer mutation detection.

Dose-volume histogram parameters for predicting radiation pneumonitis using receiver operating characteristic curve.

OBJECTIVE: To assess the predictability of dose-volume histogram (DVH) parameters for radiation pneumonitis (RP) using receiver operating characteristic (ROC) curve. METHODS: One hundred and thirty-five cases of locally advanced non-small cell lung cancer patients treated with three-dimensional radiotherapy and chemotherapy were analyzed retrospectively. The end point of follow-up was ≥2 grade RP defined according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0. The ROC curve was used to explore the predictive sensitivity (SEN), specificity (SPE), positive predictive value (PPV), and negative predictive value (NPV) for potential DVH parameters associated with RP. RESULTS: Relative volumes of total lungs receiving ≥5 Gy (V(5)), ≥10 Gy (V(10)), ≥13 Gy (V(13)), ≥20 Gy (V(20)), and mean lung dose (MLD), were all correlated to the development of RP (p < 0.05), among which V 5 and V 20 were the most important factors (p = 0.045 and 0.037; OR = 3.166 and 3.030). However, collinearity was found between V(5) and V(20) (Spearman's rho 0.771, p < 0.01). The area under the ROC curve was 0.643 and 0.648 for using V(5) and V(20) as predictors. If predictive cut-off values were established as follows: V(5) = 0.8 and V(20) = 0.3, the parameters could provide predictive SEN, SPE, PPV and NPV were 0.387 and 0.581, 0.882 and 0.701, 0.444 and 0.321, and 0.855 and 0.873, respectively. CONCLUSIONS: V(5) and V(20) could act as predictors for RP; however, single DVH metrics did not appear to have high predictive power for RP.

Molecular structure-affinity relationship of dietary flavonoids for bovine serum albumin

The relationship between the molecular structure of dietary flavonoids and their affinities for bovine serum albumin (BSA) were fully investigated by fluorescence titration analysis. The binding process with BSA was significantly affected by the molecular structure of flavonoids under study. The methylation of hydroxyl group in flavonoids enhanced their binding affinities for BSA by 1 to 794 times. Hydroxylation on rings A, B and C also strongly influenced the affinity for BSA. The glycosylation weakened the affinities for BSA by 1-2 orders of magnitude depending on the conjugation site and the class of sugar moiety. The hydrogenation of the C2=C3 double bond slightly increased the binding affinity. The galloylated catechins and pyrogallol-type catechins exhibited higher binding affinities for BSA than non-galloylated and catechol-type catechins, respectively. The affinities for BSA increased with increasing partition coefficients and decreased with increasing hydrogen bond donor and acceptor numbers of flavonoids, which suggested that the binding interaction was mainly caused by hydrophobic forces.

Improving outcomes in infants of HIV-infected women in a developing country setting.

BACKGROUND: Since 1999 GHESKIO, a large voluntary counseling and HIV testing center in Port-au-Prince, Haiti, has had an ongoing collaboration with the Haitian Ministry of Health to reduce the rate of mother to child HIV transmission. There are limited data on the ability to administer complex regimens for reducing mother to child transmission and on risk factors for continued transmission and infant mortality within programmatic settings in developing countries. METHODS AND FINDINGS: We analyzed data from 551 infants born to HIV-infected mothers seen at GHESKIO, between 1999 and 2005. HIV-infected mothers and their infants were given "short-course" monotherapy with antiretrovirals for prophylaxis; and, since 2003, highly active antiretroviral therapy (HAART) when clinical or laboratory indications were met. Infected women seen in the pre-treatment era had 27% transmission rates, falling to 10% in this cohort of 551 infants, and to only 1.9% in infants of women on HAART. Mortality rate after HAART introduction (0.12 per year of follow-up [0.08-0.16]) was significantly lower than the period before the availability of such therapy (0.23 [0.16-0.30], P<0.0001). The effects of maternal health, infant feeding, completeness of prophylaxis, and birth weight on mortality and transmission were determined using univariate and multivariate analysis. Infant HIV-1 infection and low birth weight were associated with infant mortality in less than 15 month olds in multivariate analysis. CONCLUSIONS: Our findings demonstrate success in prevention of mother-to-child HIV transmission and mortality in a highly resource constrained setting. Elements contributing to programmatic success include provision of HAART in the context of a comprehensive program with pre and postnatal care for both mother and infant.

Poor immune responses to a birth dose of diphtheria, tetanus, and acellular pertussis vaccine.

OBJECTIVES: To evaluate the safety and immunogenicity of an additional birth dose of diphtheria, tetanus, and acellular pertussis vaccine (DTaP). STUDY DESIGN: Fifty infants between 2 to 14 days of age were randomly assigned to receive either DTaP and hepatitis B vaccines (experimental) or hepatitis B alone (control) at birth. At 2, 4, 6, and 17 months of age, DTaP and routine vaccines were administered to both groups. Safety data were collected after each dose, and sera were obtained at birth, 6, 7, 17, and 18 months. Immune responses to pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae were measured by enzyme-linked immunosorbent assay; responses to other vaccines were assessed. RESULTS: No differences were seen between the 2 groups in either local or systemic reactions; all vaccines were well tolerated. Compared with the control group, infants in the experimental group demonstrated significantly lower geometric mean antibody concentrations for pertussis toxin and pertactin 6, 7, and 18 months, for fimbrae at 6, 7, 17, and 18 months, and for FHA at 18 months, and lower geometric mean antibody concentrations for diphtheria at 7 months. Immune responses to all other vaccine antigens were comparable. CONCLUSION: Administration of an additional dose of DTaP at birth was safe but was associated with a significantly lower response to diphtheria and 3 of 4 pertussis antigens compared with controls.