DNA methylation-mediated epigenetic regulation of oncogenic RPS2 as a novel therapeutic target and biomarker in hepatocellular carcinoma.

Ribosomal Protein S2 (RPS2) has emerged as a potential prognostic biomarker due to its involvement in key cellular processes and its altered expression pattern in certain types of cancer. However, its role in hepatocellular carcinoma (HCC) has yet to be investigated. Herein, we analyzed RPS2 mRNA expression and promoter methylation in HCC patient samples and HepG2 cells. Subsequently, loss-of-function experiments were conducted to determine the function of RPS2 in HCC cells in vitro. Our results revealed that RPS2 mRNA expression is significantly elevated, and its promoter is hypomethylated in HCC patient samples compared to controls. In addition, 5-Azacytidine treatment in HepG2 cells decreased RPS2 promoter methylation level and increased its mRNA expression. RPS2 knockdown in HepG2 cells suppressed cell proliferation and promoted apoptosis. Functional pathway analysis of genes positively and negatively associated with RPS2 expression in HCC showed enrichment in ribosomal biogenesis, translation machinery, cell cycle regulation, and DNA processing. Furthermore, utilizing drug-protein 3D docking, we found that doxorubicin, sorafenib, and 5-Fluorouracil, showed high affinity to the active sites of RPS2, and in vitro treatment with these drugs reduced RPS2 expression. For the first time, we report on DNA methylation-mediated epigenetic regulation of RPS2 and its oncogenic role in HCC. Our findings suggest that RPS2 plays a significant role in the development and progression of HCC, hence its potential prognostic and therapeutic utility. Moreover, as epigenetic changes happen early in cancer development, RPS2 may serve as a potential biomarker for tumor progression.

Sclareol induces cell cycle arrest and ROS-mediated apoptosis and ferroptosis in lung adenocarcinoma cells.

Sclareol (SC) has shown significant anticancer activity against breast and colon cancers among others. However, its ability to precipitate similar anticancer effects in lung cancer has yet to be investigated. To address this issue, SC-treated lung adenocarcinoma cells (A549) were assessed for viability and functional competence as well as the expression of genes related to apoptosis and cell cycling. Our results demonstrated that SC treatment inhibited A549 cell clonogenic features and reduced their migration and invasion potential in a dose-dependent manner. Mechanistically, SC treatment downregulated the expression of cyclin D1 and survivin and upregulated that of p21 and p16, which was associated with a significant increase in the percentage of SubG0 cells. SC treatment is also associated with the induction of both the extrinsic and intrinsic apoptotic pathways, as evidenced by the increased expression and splitting of PARP1 and procaspases 3 and 9 and the reduced expression of antiapoptotic proteins Bcl-2 and Bcl-xL. Increased cell death in SC-treated cells is likely to have resulted from the induction of ferroptosis as suggested by the reduced expression of FPN and the inhibition of the anti-ferroptosis regulator GPX4. In conclusion, the data presented here suggest that SC can reduce lung carcinoma cell growth and metastasis and promote cell death.

Estrogen treatment in combination with pyruvate kinase M2 inhibition precipitate significant cumulative antitumor effects in colorectal cancer.

It is well established that pyruvate kinase M2 (PKM2) activity contributes to metabolic reprogramming in various cancers, including colorectal cancer (CRC). Estrogen or 17ß-estradiol (E2) signaling is also known to modulate glycolysis markers in cancer cells. However, whether the inhibition of PKM2 combined with E2 treatment could adversely affect glucose metabolism in CRC cells remains to be investigated. First, we confirmed the metabolic plasticity of CRC cells under varying environmental conditions. Next, we identified glycolysis markers that were upregulated in CRC patients and assessed in vitro mRNA levels following E2 treatment. We found that PKM2 expression, which is highly upregulated in CRC clinical samples, is not altered by E2 treatment in CRC cells. In this study, glucose uptake, generation of reactive oxygen species (ROS), lactate production, cell viability, and apoptosis were evaluated in CRC cells following E2 treatment, PKM2 silencing, or a combination of both. Compared to individual treatments, combination therapy resulted in a significant reduction in cell viability and enhanced apoptosis. Glucose uptake and ROS production were markedly reduced in PKM2-silenced E2-treated cells. The data presented here suggest that E2 signaling combined with PKM2 inhibition cumulatively targets glucose metabolism in a manner that negatively impacts CRC cell growth. These findings hold promise for novel therapeutic strategies targeting altered metabolic pathways in CRC.

Protective effects of baicalin against phenylarsine oxide-induced cytotoxicity in human skin keratinocytes.

Phenylarsine oxide (PAO) is a known environmental pollutant and skin keratinocytes are most seriously affected. Baicalin (BCN) was reported to have antioxidant and anti-inflammatory effects, but its protective effect against PAO toxicity is unknown. This study aimed at exploring whether baicalin can reverse the toxicity of human epidermal keratinocytes that are subjected to PAO exposure and underlying mechanisms. In silico analysis from a publicly accessible HaCaT cell transcriptome dataset exposed to chronic Arsenic showed significant differential expression of several genes, including the genes related to DNA replication. Later, we performed in vitro experiments, in which HaCaT cells were exposed to PAO (500 nM) in the existence of BCN (10-50 µM). Treatment of PAO alone induces the JNK, p38 and caspase-3 activation, which were engaged in the apoptosis induction, while the activity of AKT was significantly inhibited, which was engaged in the suppression of apoptosis. PAO suppressed SIRT3 expression and induced intracellular reactive oxygen species (ROS), causing a marked reduce in cell viability and apoptosis. However, BCN treatment restored the PAO-induced suppression of SIRT3 and AKT expression, reduced intracellular ROS generation, and markedly suppressed both caspase-3 activation and apoptosis induction. However, the protective effect of BCN was significantly attenuated after pretreatment with nicotinamide, an inhibitor of SIRT3. These findings indicate that BCN protects against cell death induced by PAO via inhibiting excessive intracellular ROS generation via restoring SIRT3 activity and reactivating downstream AKT pathway. In this study, we firstly shown that BCN is an efficient drug to prevent PAO-induced skin cytotoxicity, and these findings need to be confirmed by in vivo and clinical investigations.

Colonic TRPV4 overexpression is related to constipation severity.

BACKGROUND: Chronic constipation is prevalent and involves both colon sensitivity and various changes in intestinal bacteria, particularly mucosa-associated microflora. Here we examined regulatory mechanisms of TRPV4 expression by co-culturing colon epithelial cell lines with intestinal bacteria and their derivatives. We also investigated TRPV4 expression in colon epithelium from patients with constipation. METHODS: Colon epithelial cell lines were co-cultured with various enterobacteria (bacterial components and supernatant), folate, LPS, or short chain fatty acids. TRPV4 expression levels and promoter DNA methylation were assessed using pyrosequencing, and microarray network analysis. For human samples, correlation coefficients were calculated and multiple regression analyses were used to examine the association between clinical background, rectal TRPV4 expression level and mucosa-associated microbiota. RESULTS: Co-culture of CCD841 cells with P. acnes, C. perfringens, or S. aureus transiently decreased TRPV4 expression but did not induce methylation. Co-culture with clinical isolates and standard strains of K. oxytoca, E. faecalis, or E. coli increased TRPV4 expression in CCD841 cells, and TRPV4 and TNF-alpha expression were increased by E. coli culture supernatants but not bacterial components. Although folate, LPS, IL-6, TNF-alpha, or SCFAs alone did not alter TRPV4 expression, TRPV4 expression following exposure to E. coli culture supernatants was inhibited by butyrate or TNF-alphaR1 inhibitor and increased by p38 inhibitor. Microarray network analysis showed activation of TNF-alpha, cytokines, and NOD signaling. TRPV4 expression was higher in constipated patients from the terminal ileum to the colorectum, and multiple regression analyses showed that low stool frequency, frequency of defecation aids, and duration were associated with TRPV4 expression. Meanwhile, incomplete defecation, time required to defecate, and number of defecation failures per 24 h were associated with increased E. faecalis frequency. CONCLUSIONS: Colon epithelium cells had increased TRPV4 expression upon co-culture with K. oxytoca, E. faecalis, or E. coli supernatants, as well as TNFα-stimulated TNFαR1 expression via a pathway other than p38. Butyrate treatment suppressed this increase. Epithelial TRPV4 expression was increased in constipated patients, suggesting that TRPV4 together with increased frequency of E. faecalis may be involved in the pathogenesis of various constipation symptoms.

DNA Methylation-Mediated Overexpression of CXCL1 in Helicobacter pylori-Induced Gastric Cancer: In Silico- and In Vitro-Based Identification of a Potential Biomarker for Carcinogenesis.

Given the high global prevalence and mortality associated with gastric cancer, and its known causal link with Helicobacter pylori infection, it is important to have a biomarker to identify malignant transformation at early stages. Previously, we, and others, have reported that H. pylori-induced epigenetic changes could mediate carcinogenic transformation of the gastric cells. Also, CXCL1 secreted by gastric cancer cells was reported as a key diagnostic and prognostic biomarker for the pathogenic progression of gastric cancer. In this study, for the first time, we aimed to investigate the role of H. pylori-induced DNA methylation-based epigenetic regulation of CXCL1. In silico analysis of publicly available datasets and in vitro experiments were performed. Our results showed that CXCL1 is highly expressed in both gastric cancer tissues and gastric cancer cells infected with H. pylori. Further, we showed and confirmed that H. pylori-mediated overexpression of CXCL1 is due to hypomethylation of its promoter region. Since epigenetic events such as DNA methylation happen early in the sequence; H. pylori-induced CXCL1 hypomethylation could likely be detected at an early stage of gastric cancer development. Epigenetic modifications, such as CXCL1 hypomethylation, are reversible and could potentially be a therapeutic target using demethylation drugs.

Association of the BB genotype of the ABO gene with the risk of acute myocardial infarction in hospital-based study.

Objectives: The ABO gene locus has been identified to be associated with myocardial infarction in patients with coronary heart disease. The primary focus of this hospital-based study was to explore the relationship of ABO blood groups and ABO genotypes with acute myocardial infarction (AMI) in Karachi, Pakistan. Methods: In a comparative cross-sectional study, an equal number of adult AMI patients and healthy controls (n=275 in each group; age range 30-70 years, both males and females) were recruited from the Aga Khan University and NICVD, Karachi, with informed consent. The blood samples were analyzed for ABO blood groups and other biomarkers. PCR followed by RFLP techniques were employed for determining the ABO genotypes. Multinomial regression was used to evaluate the association of genotypes with the risk of AMI. Results: Thirteen different combinations of ABO genotypes were observed while the O2O2 and A2A2 genotypes were not detected. No significant association based on the distribution of blood groups A, B, O and AB among AMI patients and healthy individuals was observed. The odds of AMI were 3.32 times in subjects with BB genotype as compared to subjects with OO genotypes after adjustment of age, gender, body mass index, heart rate, total cholesterol, and waist circumference [AOR (95% CI) =3.32 (1.36-8.08), p-value =0.008]. Conclusion: Our hospital-based study indicates that ABO genotype BB was significantly associated with the risk of AMI. This harmful effect of the BB genotype could have a possible relationship with AMI's development in the Pakistani population.

SARS-CoV-2-induced hypomethylation of the ferritin heavy chain (FTH1) gene underlies serum hyperferritinemia in severe COVID-19 patients.

High serum ferritin (hyperferritinemia), a reliable hallmark of severe COVID-19 often associates with a moderate decrease in serum iron (hypoferremia) and a moderate increase in serum hepcidin. This suggests that hyperferritinemia in severe COVID-19 is reflective of inflammation rather than iron overload. To test this possibility, the expression status of ferritin heavy chain (FTH1), transferrin receptor 1 (TFRC), hepcidin (HAMP), and ferroportin (SLC40A1) genes and promoter methylation status of FTH1 and TFRC genes were examined in blood samples obtained from COVID-19 patients showing no, mild or severe symptoms and in healthy-donor monocytes stimulated with SARS-CoV-2-derived peptides. Severe COVID-19 samples showed a significant increase in FTH1 expression and hypomethylation relative to mild or asymptomatic COVID-19 samples. S-peptide treated monocytes also showed a significant increase in FTH1 expression and hypomethylation relative to that in controls; treatment with ECD or NP did not change FTH1 expression nor its methylation status. In silico and in vitro analysis showed a significant increase in the expression of the TET3 demethylase in S peptide-treated monocytes. Findings presented here suggest that S peptide-driven hypomethylation of the FTH1 gene promoter underlies hyperferritinemia in severe COVID-19 disease.

Lack of association of HFE gene polymorphism with high body iron status in Pakistani patients with type 2 diabetes mellitus.

OBJECTIVE: The Aim of this study was to investigate the relationship of 3 common polymorphisms in the HFE gene (C282Y, H63D and S65C) with high body iron status in a population of Pakistani subjects with type 2 diabetes mellitus (DM) and to explore if there is any novel mutation in HFE gene in a sample of Pakistani subjects with type 2 DM. METHODS: In a case-control design, 200 healthy controls and 200 consecutive adult subjects with type 2 DM (both gender; age range of 30-70 years) were enrolled with informed consent. Their serum samples were analyzed for body iron status (ratio of concentration of soluble transferrin receptor to ferritin concentration). DNA from blood was screened for HFE gene polymorphisms via polymerase chain reaction, followed by restriction fragment length polymorphism or via Sanger sequencing to identify any novel mutation(s) in HFE gene. RESULTS: We found that there was lack of any association between HFE polymorphism and body iron status in Pakistani subjects with type 2 DM and healthy controls. H63D was the most common polymorphism found in this population. Single base substitution of G nucleotide instead of C at the codon position 187 in the HFE gene exon 2 was discovered in one subject with DM. There was also a lack of association between D allele (variant allele of H63D) and type 2 DM. A significant relationship was found between CG genotype and abnormal albuminuria in subjects with type 2 DM (p = 0.036). CONCLUSION: In conclusion, HFE gene polymorphism is not associated either with high body iron status or type 2 DM in a hospital based Pakistani population and variant allele of H63D polymorphism appears to be associated with diabetic nephropathy.

The Role of K-Ras and P53 in Biliary Tract Carcinoma.

OBJECTIVE: To focus mainly on the role of proto-oncogene Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (K-Ras) and tumour-suppressor gene p53 which are among the most commonly mutated genes in biliary tract carcinomas. METHODS: The systematic review comprised research articles published between 2002 and 2019 on PubMed and Google Scholar databases which were searched using the terms 'TP53', 'K-Ras', 'mutation', 'biliary tract carcinoma', 'cholangiocarcinoma', and 'murine model'. Repetitions, duplicates and irrelevant articles were excluded. No data was retrieved from posters, presentations and symposiums, and experiments involving bile aspirations were also excluded. RESULTS: Of the 72 articles reviewed, 11(15.3%) were included. Of them, 3(27.3%) studies, conducted in China, Japan and Taiwan, reported a positive correlation between K-Ras mutation and biliary tract carcinoma. Only 1(9%) study, conducted in China, showed the sole correlation between p53 inactivation and biliary tract carcinoma. Also, 4(36.4%) studies, conducted in China, Japan and Europe, showed a positive association of both K-Ras mutation and p53 inactivation with biliary tract carcinoma. CONCLUSIONS: K-Ras and p53 mutation both contribute to biliary tract carcinoma. K-Ras mutation, however, has a much higher frequency compared to p53 inactivation in such cancers.

In vitro and in vivo anti-Helicobacter pylori activity of selected medicinal plants employed for the management of gastrointestinal disorders.

Five medicinal plants Mentha piperita L., Trachyspermum ammi L., Viola odorata Linn., Matricaria chamomilla L. and Foeniculum vulgare Mill. were selected for their in vitro and in vivo evaluation of anti-Helicobacter pylori activity. In vitro evaluation was performed by using disk diffusion method and minimum inhibitory concentrations were noted while rat models were selected for in vivo activity against four Helicobacter pylori strains isolated form gastric mucosa. Mentha piperita showed largest zone of inhibition with 9 mm diameter among all other extracts. All the plants showed promising anti-Helicobacter pylori activity against four isolates and a reference strain at concentrations of 125, 250, 500 and 1000 µg/ml in comparison with Amoxicillin 1 µg/ml but least MIC was exhibited by Mentha piperita followed by in vivo testing where it competed Amoxicillin at 1000 mg/kg by achieving 80% eradication of Helicobacter pylori in mucosa of infected rats justified by histological examination of stomach. It was concluded that medicinal plants possess strong anti-Helicobacter pylori activity and can be considered a potential source of safe and effective alternative regimens for the eradication of Helicobacter pylori.

Autophagy impairment by Helicobacter pylori-induced methylation silencing of MAP1LC3Av1 promotes gastric carcinogenesis.

Helicobacter pylori (H. pylori) infection induces methylation silencing of tumor suppressor genes causing gastric carcinogenesis. Impairment of autophagy induces DNA damage leading to genetic instability and carcinogenesis. We aimed to identify whether H. pylori infection induced methylation silencing of host autophagy-related (Atg) genes, impairing autophagy and enhancing gastric carcinogenesis. Gastric mucosae were obtained from 41 gastric cancer patients and 11 healthy volunteers (8 H. pylori-uninfected and 3 H. pylori-infected). Methylation status of Atg genes was analyzed by a methylation microarray and quantitative methylation-specific PCR (qMSP); mRNA expression was assessed by quantitative reverse transcription PCR (qRT-PCR). Cell proliferation, migration and invasion were assessed in normal rat gastric epithelial cells. Gene knock-down was performed by siRNA. Autophagy was assessed by western blotting. Of 34 Atg genes, MAP1LC3A variant 1 (MAP1LC3Av1) and ULK2 were identified by methylation microarray analysis as exhibiting specific methylation in H. pylori-infected mucosae and gastric cancer tissues. Methylation silencing of MAP1LC3Av1 was confirmed by qMSP, qRT-PCR and de-methylation treatment in two gastric cancer cell lines. Knock-down of map1lc3a, the rat homolog of the human MAP1LC3Av1, inhibited autophagy response and increased cell proliferation, migration and invasion in normal rat gastric epithelial cells, despite the presence of map1lc3b, the rat homolog of the human MAP1LC3B gene important for autophagy. Furthermore, MAP1LC3Av1 was methylation-silenced in 23.3% of gastric cancerous mucosae and 40% of non-cancerous mucosae with H. pylori infection. MAP1LC3Av1 is essential for autophagy and H. pylori-induced methylation silencing of MAP1LC3Av1 may impair autophagy, facilitating gastric carcinogenesis.

Transient receptor potential vanilloid 4 (TRPV4) silencing in Helicobacter pylori-infected human gastric epithelium.

BACKGROUND: Helicobacter pylori (HP) infection induces methylation silencing of specific genes in gastric epithelium. Various stimuli activate the nonselective cation channel TRPV4, which is expressed in gastric epithelium where it detects mechanical stimuli and promotes ATP release. As CpG islands in TRPV4 are methylated in HP-infected gastric epithelium, we evaluated HP infection-dependent changes in TRPV4 expression in gastric epithelium. MATERIALS AND METHODS: Human gastric biopsy samples, a human gastric cancer cell line (AGS), and a normal gastric epithelial cell line (GES-1) were used to detect TRPV4 mRNA and protein expression by RT-PCR and Western blotting, respectively. Ca2+ imaging was used to evaluate TRPV4 ion channel activity. TRPV4 methylation status was assessed by methylation-specific PCR (MSP). ATP release was measured by a luciferin-luciferase assay. RESULTS: TRPV4 mRNA and protein were detected in human gastric biopsy samples and in GES-1 cells. MSP and demethylation assays showed TRPV4 methylation silencing in AGS cells. HP coculture directly induced methylation silencing of TRPV4 in GES-1 cells. In human samples, HP infection was associated with TRPV4 methylation silencing that recovered after HP eradication in a time-dependent manner. CONCLUSION: HP infection-dependent DNA methylation suppressed TRPV4 expression in human gastric epithelia, suggesting that TRPV4 methylation may be involved in HP-associated dyspepsia.

Current status of Helicobacter pylori association with haematological and cardiovascular diseases: A mini review.

Helicobacter pylori infection is considered the most commonly prevalent gastrointestinal pathogen where it manages to survive despite the hostile environment of human stomach, leading to various gastric diseases including gastric cancer. Due to the chronic inflammatory state induced by H. pylori and its interaction with host immune system have diverted researchers to investigate its correlation with systemic diseases outside of the gastrointestinal tract. This literature review was done to explore the association of H. pylori infection with haematological and cardiovascular diseases. We used medical subject heading (MeSH) terms "Helicobacter pylori" with "inflammation," "haematological diseases," "coronary heart diseases" or "vascular diseases" to search PubMed database. All relevant studies identified from 2005 to 2015 were included. As many of the studies are small-scale or showed weak association, further studies are needed to address the role of H. pylori in pathogenesis of haematological and cardiovascular diseases.

Anti-inflammatory effect of cinnamaldehyde in Helicobacter pylori induced gastric inflammation.

Cinnamomum cassia is widely employed for gastrointestinal complaints such as dyspepsia, flatulence, diarrhea, and vomiting. Studies report cinnamaldehyde (CM) as a major active constituent of cinnamon. The aim of this study was to evaluate the anti-inflammatory mechanism of CM on Helicobacter (H.) pylori-infected gastric epithelial cells in order to validate cinnamon traditional use in gastrointestinal (GI)-related disorders. AGS/MKN-45 cells and H. pylori (193C) were employed for co-culture experiments. Anti-H. pylori cytotoxic and anti-adhesion activity of CM were determined. Enzyme linked immunosorbent assay, real time polymerase chain reaction analysis and immunoblotting were used to measure the effect on interleukin-8 (IL-8) secretion/expression. The effect on activation of nuclear factor kappa B (NF-κB) was determined by immunoblot analysis. The non-cytotoxic CM (≤125 µM) was also non-bactericidal at the given time, suggesting the effect in H. pylori/cell co-culture system was not due to alteration in H. pylori viability or the toxicity to the cells. Also, CM did not show any anti-adhesion effect against H. pylori/cell co-culture. However, pre-incubation of the cells with CM significantly inhibited the IL-8 secretion/expression from H. pylori-infected cells (p<0.01). In addition, CM suppressed H. pylori-induced NF-κB activation and prevented degradation of inhibitor (I)-κB This study provides evidence that the anti-inflammatory effect of C. cassia on H. pylori-infected gastric cells is due to blockage of the NF-κB pathway by cinnamaldehyde. This agent can be considered as a potential candidate for in vivo and clinical studies against various H. pylori related gastric pathogenic processes.

Review: Diverse pharmacological properties of Cinnamomum cassia: A review.

Cinnamomum cassia is widely utilized as a spice in different cookeries worldwide, especially in Asian cuisines. This herb is also being used in different forms of traditional medicine (Unani, Ayurvedic, Japanese and Chinese) for managing conditions like dyspepsia, peptic ulcer disease and ischemic brain injury. Recent studies have shown the scientific evidence for the medicinal use of this particular herb in several diseases like H. pylori infection, diabetes, brain ischemia and cancers. This article reviews the literature on potential benefits of the herb published within the last 10 years. The authors used Medical Subject Headings (MeSH) terms "Cinnamomum" with "cassia" or "arromaticum" to filter the PubMed database. To date, no systemic review focusing on medicinal use of C. cassia was found in the literature. Various research articles elucidating diverse pharmacological properties of C. cassia were identified. The standardised extract of C. cassia or the active compounds extracted from the herb might prove to be a novel candidate for early prevention and complimentary management of conditions like diabetes mellitus or H. pylori-associated disorders.

Review: Pharmacological ins and outs of medicinal plants against Helicobacter pylori: A review.

Since Helicobacter pylori was discovered in 1980, it has been considered as a major cause in the pathogenesis of gastric ulcer, mucosa-associated lymphoid tissue (MALT) lymphomas, and gastric cancer. Eventually antibiotics were designed to eradicate this bacterium, which not only prevent peptic ulcer recurrence but also decrease the chances of developing gastric cancer. Propitious consequences of these antibiotic regimens and better hygienic conditions, particularly in developed countries, resulted in significant decline in the prevalence of H. pylori infection. However, persistent high H. pylori infection in developing countries, decreased patience compliance and emerging antibiotic resistance forced researchers to quest for novel candidates. Herbal medicines have always served as a leading source in drug discovery. Since time immemorial, herbs have been used to treat various disorders covering from minor illnesses as pain to life threatening conditions like cancer. Ample amount of studies from different parts of the world have shown promising activities of medicinal herbs not only against H. pylori but also associated disorders while employing in vitro, in vivo and clinical studies. In this review, these multiple pharmacological effects of medicinal plants and their chemical constituents will be discussed in relation to H. pylori not only to scientifically evaluate the beneficial effects of these medicinal plants but to also critically analyze their plausible role as chemo preventive agents against H. pylori-associated disorders.

Iron Overloading Potentiates the Antitumor Activity of 5-Fluorouracil by Promoting Apoptosis and Ferroptosis in Colorectal Cancer Cells.

Resistance to 5-fluorouracil (5-FU) remains a significant challenge in colorectal cancer (CRC) treatment. Ferric ammonium citrate (FAC) is commonly used as an iron supplement due to its food-fortification properties; however, its potential role as a chemosensitizer in cancer therapy has not been studied. In this study, we explored the ability of FAC to sensitize CRC cells and increase their susceptibility to 5-FU-mediated anticancer effects. We assessed cell viability, cell cycle progression, apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, ferroptosis, and iron metabolism-related protein expression using two CRC cell lines. Additionally, we conducted in silico analyses to compare iron markers in normal colon and CRC tumor tissues. Compared to controls, CRC cells pretreated with FAC and then treated with 5-FU exhibited significantly reduced growth and viability, along with increased ROS-mediated ferroptosis. Mechanistically, FAC-pretreated then 5-FU-treated CRC cells showed enhanced apoptosis, increased Bak/Bax expression, MMP depolarization, and decreased antiapoptotic protein levels (Bcl-2 and Bcl-xL). This combined treatment also led to G2/M cell cycle arrest, upregulation of p21 and p27, and downregulation of cyclin D1, c-Myc, survivin, and GPX4. Analysis of human colon tumor tissue revealed decreased expression of IRP-1, HMOX-1, and FTH1 but increased HAMP expression. In contrast, FAC-pretreated/5-FU-treated CRC cells exhibited a reverse pattern, suggesting that FAC-induced chemosensitization enhances 5-FU-mediated anticancer activity in CRC by disrupting iron homeostasis. These findings highlight the potential of iron overload as a chemosensitization strategy for improving CRC chemotherapy.

Prevalence of Imposter Syndrome and Its Risk Factors Among University of Sharjah Medical Students.

Background Imposter syndrome describes an internal experience of intellectual fraud, where individuals attribute their academic or occupational endeavors and achievements primarily to luck rather than to their diligent efforts. Additionally, the stringent standards and prerequisites set by medical institutions create an environment conducive to impostorism among medical students. This study aimed to evaluate the prevalence and severity of imposter syndrome among medical students at the University of Sharjah. Methodology This research was designed as a descriptive cross-sectional study. A total of 400 participants enrolled in the study using non-probability convenience sampling, but 399 participants, 49.4% (197) from colleges of medicine and 50.6% (202) from dentistry, successfully completed the questionnaire. Participants completed a questionnaire containing the Clance Imposter Phenomenon Scale. Statistical associations between variables were tested using the chi-square test. Individuals with chronic medical conditions or those using medications with known psychiatric side effects were excluded. Results The analyzed sample comprised 399 students, with 64.7% females and 35.3% males. Most respondents were from year 2 (21.3%, 85), while the fewest were from year 5 (18.3%, 73). The majority of students fell into the categories of moderate (46.4%, 185) and frequent (35.8%, 143) imposter experiences. Among all investigated characteristics, pure academic factors such as field of study (p = 0.001), study phases (p = 0.032), advisor's attitude (p = 0.029), and comparison with peers' performance and grades (p = 0.024 and <0.001, respectively) exhibited the highest significant association with the severity of imposter syndrome. Conclusions This study revealed a high prevalence of imposter syndrome among medical students, emphasizing the need for comprehensive strategies and interventions targeting academically associated risk factors to alleviate the burden of imposter syndrome.

Inhibition of PRMT5-mediated regulation of DKK1 sensitizes colorectal cancer cells to chemotherapy.

The Dickkopf family proteins (DKKs) are strong Wnt signaling antagonists that play a significant role in colorectal cancer (CRC) development and progression. Recent work has shown that DKKs, mainly DKK1, are associated with the induction of chemoresistance in CRC and that DKK1 expression in cancer cells correlates with that of protein arginine N-methyltransferase 5 (PRMT5). This points to the presence of a regulatory loop between DKK1 and PRMT5. Herein, we addressed the question of whether PRMT5 contributes to DKK1 expression in CRC and hence CRC chemoresistance. Both in silico and in vitro approaches were used to explore the relationship between PRMT5 and different DKK members. Our data demonstrated that DKK1 expression is significantly upregulated in CRC clinical samples, KRAS-mutated CRC in particular and that the levels of DKK1 positively correlate with PRMT5 activation. Chromatin immunoprecipitation (ChIP) data indicated a possible epigenetic role of PRMT5 in regulating DKK1, possibly through the symmetric dimethylation of H3R8. Knockdown of DKK1 or treatment with the PRMT5 inhibitor CMP5 in combination with doxorubicin yielded a synergistic anti-tumor effect in KRAS mutant, but not KRAS wild-type, CRC cells. These findings suggest that PRMT5 regulates DKK1 expression in CRC and that inhibition of PRMT5 modulates DKK1 expression in such a way that reduces CRC cell growth.