Modulation of cancer signalling pathway(s) in two-stage mouse skin tumorigenesis by annonacin

Background: Annonacin, an annonaceous acetogenin isolated from Annona muricata has been reported to be strongly cytotoxic against various cell lines, in vitro. Nevertheless, its effect against in vivo tumor promoting activity has not been reported yet. Therefore, this study was aimed to investigate antitumor-promoting activity of annonacin via in vivo two-stage mouse skin tumorigenesis model and its molecular pathways involved. Methods: Mice were initiated with single dose of 7,12-dimethylbenz[α]anthracene (DMBA) (390 nmol/100 μL) followed by, in subsequent week, repeated promotion (twice weekly; 22 weeks) with 12-O-tetradecanoylphorbol-13-acetate (TPA) (1.7 nmol/100 μL). Annonacin (85 nM) and curcumin (10 mg/kg; reference) were, respectively, applied topically to DMBA/TPA-induced mice 30 min before each TPA application for 22 weeks. Upon termination, histopathological examination of skin, liver and kidney as well as genes and proteins expression analysis were conducted to elucidate the potential mechanism of annonacin. Results: With comparison to the carcinogen control, Annonacin significantly increased the tumor latency period and reduced the tumor incidence, tumor burden and tumor volume, respectively. In addition, it also suppressed tumorigenesis manifested by significant reduction of hyperkeratosis, dermal papillae and number of keratin pearls on skin tissues. Annonacin also appeared to be non-toxic to liver and kidney. Significant modulation of both AKT, ERK, mTOR, p38, PTEN and Src genes and proteins were also observed in annonacin-targeted signaling pathway(s) against tumorigenesis. Conclusions: Collectively, results of this study indicate that annonacin is a potential therapeutic compound targeting tumor promoting stage in skin tumorigenesis by modulating multiple gene and protein in cancer signaling pathways without apparent toxicity

Annona muricata leaves extracts prevent DMBA/TPA-induced skin tumorigenesis via modulating antioxidants enzyme system in ICR mice

Annona muricata, locally known as soursop has been reported to exhibit antiproliferative activities against various cancer cell lines. In this current study, we have investigated the antitumor promotion of various fractions of Annona muricata leaves (AML); hexane (AMLH), dichloromethane (AMLD) and methanol (AMLM) fraction respectively on 7, 12-dimethylbenz[α]anthracene (DMBA) induced and 12-0-tetradecaboylphorbol-13-acetate (TPA) promoted skin tumorigenesis in mice via morphological assessment, biochemical analysis and histopathological evaluation. The results of the study revealed significant inhibition in tumor incidence, tumor burden and tumor volume in the groups received AMLH and AMLD, respectively, and suppressive effects in group received AMLM compared with carcinogen control group at week 21. Superoxide dismutase, catalase, and lipid peroxidation levels were returned to near normal by administration of AML to DMBA/TPA-induced mice. The above findings were supported by histopathological studies, in which the extensive epidermal hyperplasia in carcinogen control group was restored to normal in AML treated groups. Whilst, annonacin, a major annaonaceous acetogenin was found to be the highest in AMLH and AMLD. From the present study, it can be inferred that AML supressed DMBA/TPA-induced skin tumor and this antitumor-promoting activity may be linked to the antioxidant/free radical-scavenging constituents of the extract and annonacin contained in the extracts

Expression of cyclooxygenase-2(COX-2) and cyclin dependent kinase 1B (CDKN1B/p27Kip1) in human prostatet adenocarcinoma

Prostate adenocarcinoma is one of the most common forms of malignancy occurring in the Malaysian male population. Inflammation has been identified in many studies to play key roles in the process of carcinogenesis. Inflammation is responsible for prompting angiogenesis, enhancing cellular motility and increasing resistance to apoptosis. Cyclooxygenase-2 (COX-2) is an enzyme that converts arachidonic acid into proinflammatory prostaglandins and other eicosanoids. In addition, COX-2 is also highly expressed in a wide number of human cancers including prostate adenocarcinoma. Moreover, loss of Cyelin dependent kinase inhibitor IB (p27Kip) expression has been implicated in the malignant development in many human cancers. p27Kip) is a gene that encodes protein for cell cycle regulation generally, and controls the cell cycle progression at G) phase specifically. Low expression ofp27Kip) has been associated with a poor prognosis in malignant tumours, including breast, gastric and prostate carcinoma. The objectives of this study were to determine the expression level of COX-2 and p27Kipl in different types of prostate tissue and to relate the association with the clinicopathological parameters. p27Kipl (VI09G) polymorphism frequency in prostate adenocarcinoma was also determined to assess its relationship with advance prostate cancer susceptibility. Paraffin-embedded prostatic tissue (n = 263) was obtained from the Pathology Department of Hospital Kuala Lumpur. The mean age of the patients is 64.54 ±10.79 years. The tissue retrieved consisted of 63 normal prostate tissue samples, as well as 100 each for benign prostatic hyperplasia (BPH) and prostate adenocarcinoma (PCa). COX-2 expression was performed using standard immunohistochemistry methods. Anti-human COX-2 monoclonal mouse primary antibody was used in a 1:]00 dilution, whereas the anti-human p27Kipl monoclonal mouse primary antibody was used in a dilution of 1:50. For each sample, the extent and intensity of staining with COX-2 antibody was graded on a scale from 0 to 4+. Staining was classified as 0 (no expression), I+ (weak expression), 2+ (moderate expression), 3+ (strong expression) and 4+ (very strong expression). The results showed that, 561100 PCa samples showed strong COX-2 expression (P=O.OOO), in comparison 161100 samples of BPH (P=O.OO 1), while weak COX-2 expression was observed in all 63 normal samples. Very strong expression for p27Kipl was seen in 62/63 normal prostate tissue samples and 771100 BPH samples (P=O.OOO), while 39/100 PCa samples exhibited weak p27Kipl expression and 25 of the rest had no expression (P=O.OOO). Next, to confirm the accuracy of staining, we further analysed selected samples by semiquatitative reverse transcriptase PCR (RTPCR) method on COX-2 and p27Kipl genes. This RT-PCR analysis, COX-2 expression was detected in high Gleason scores of 8 and 9, which were 2.01 and 2.17-fold respectively higher compared to normal tissue. BPH displayed only 1.04-fold higher COX-2 expression than normal tissue. Significant down-regulation of p27KipJ was observed in Gleason scores 7, 8 and 9 which were less than O.5-fold in changes compared to normal prostatic tissue. No significant p27KipJdown-regulation was observed in BPH samples compared to normal samples. PCR-RFLP was used to investigate p27KipJ polymorphism using Bgl1 restriction enzyme. PCR-RFLP analysis showed that distribution of genotypes were not statistically significant between PCa and normal prostate, whereby the genotypes VV and VG were observed more frequently in PCa and normal prostate, while GG genotype was not found in any PCa or normal samples. The results of this study, suggest that COX-2 overexpression and p27KipJ down-regulation may play a role in the progression of prostate adenocarcinoma. Therefore, expression of COX-2 and p27KipJ as potential therapeutic targets for prostate cancer should be evaluated further

High expression of cyclooxygenase-2 in high grade human prostate adenocarcinoma

Inflammation plays an important role to the process of prostate carcinogenesis by increasing the rate of cell proliferation, which contributes to an aggressive tumour phenotype. Cyclooxygenase-2 (COX-2) has been found overexpressed in various types of cancer cells including prostate. The aim of this study was to investigate the COX-2 expressions in different types of human prostate tissues. Paraffin-embedded prostate tissues from 263 samples were examined for the expression of COX-2 marker by immunohistochemistry method. COX-2 was found highly expressed in prostate adenocarcinoma (p=0.001) as compared to benign and normal tissues. The score of COX-2 expressions in most of normal prostate was weak 49 (77.8%), while only 16 (16%) of BPH showed strong expression. 56 cases (56%) prostate cancer showed strong COX-2 expression. Prostate cancer cases showed significant differences in staining patterns as tumour grade increased. In addition, COX-2 expression was significantly correlated with Gleason score in cancerous tissues. This study suggests that COX-2 overexpression is associated with prostate cancer and higher grade tumour

Physiological response and impact of COVID-19 pandemic among Malaysian citizens: a cross-sectional study

Introduction: Studies have shown that staying at home for prolonged periods of crisis can pose a significant challenge to individuals and affect their mental health. Hence, this study was conducted to identify the susceptible subgroups among Malaysian citizens that are prone to mental health problems during the lockdown period of the COVID-19 pandemic and its association with sociodemographic factors. Methods: The mental health status was assessed using the Depression, Anxiety, and Stress Scale -21 (DASS-21) questionnaire. The survey link was distributed online between October and December 2020. Results: Of 637 respondents, one-third experienced mild to extremely severe depression and anxiety (31.1 and 35.1, respectively). Female respondents (odds ratio = 1.516, 95 confidence interval (CI) 1.057-2.172) were 1.5 times more likely to experience mild to severe depression than male respondents. Unmarried and divorced respondents were 2.1 times more prone to experience mild to severe depression than married respondents. A significant association was also found between employment status and age with depression symptoms among the respondents. For anxiety, a significant association was observed between the age group with mild to severe anxiety symptoms. Marital status, age, and employment status were socio-demographic factors significantly impacting stress levels. Conclusion: According to our findings, females, individuals aged 18-30 years old, students, unmarried and divorced respondents were more susceptible to mental health problems, suggesting that mental health support shall also be provided for these vulnerable groups during the COVID-19 crisis