Prevalence of tobacco use among cancer patients in Iran: a systematic review and meta-analysis.

BACKGROUND: The prevalence of tobacco use among various cancer types in Iran remains a significant concern, necessitating a comprehensive analysis to understand the extent and patterns of consumption. This study aimed to systematically review and analyze existing literature to delineate the prevalence of tobacco use across different cancer types in Iran, thereby providing a robust basis for future interventions and policy formulations. METHODS: Adhering to the PRISMA guidelines, we conducted a systematic review and meta-analysis of literature available in PubMed and Scopus databases. The initial search identified 351 records, out of which 44 studies were selected based on their relevance and design. These studies spanned various time frames, starting from the 2001s up until 2022, and encompassed diverse geographical locations and cancer types in Iran. To avoid bias and potential data overlap, we opted to incorporate a single comprehensive study from the Golestan Cohort, encompassing all data, while excluding 10 other studies. Our final analysis incorporated data from 34 studies, which accounted for 15,425 patients and 5,890 reported smokers. Statistical analyses were performed to calculate the overall proportion of tobacco consumption and to conduct subgroup analyses based on different variables such as cancer types, gender, geographical locations, and types of tobacco used. RESULTS: The analysis revealed a substantial prevalence of tobacco use among cancer patients in Iran, with an overall consumption rate of 43%. This rate varied significantly, ranging from 10 to 88% across individual studies. Subgroup analyses further highlighted disparities in tobacco consumption rates across different demographics, geographic areas, and cancer types. Notably, the 'ever' smokers category exhibited the highest prevalence of tobacco use. The study also identified a worrying trend of high cigarette smoking rates, along with variable consumption patterns of other forms of tobacco, including waterpipe, 'Naas', and 'Pipe'. CONCLUSIONS: This systematic review and meta-analysis underscores a significant association between tobacco consumption and various cancer types in Iran, with a prevalence rate among cancer patients being three times higher than the average Iranian population. The findings indicate substantial heterogeneity in tobacco use patterns, emphasizing the need for targeted interventions to address this pressing health issue. The study serves as a critical resource for shaping future policies and strategies aimed at curbing tobacco use and mitigating its adverse effects on cancer prevalence in Iran.

CRISPR-Cas system as a promising player against bacterial infection and antibiotic resistance.

The phenomenon of antibiotic resistance (AR) and its increasing global trends and destructive waves concerns patients and the healthcare system. In order to combat AR, it is necessary to explore new strategies when the current antibiotics fail to be effective. Thus, knowing the resistance mechanisms and appropriate diagnosis of bacterial infections may help enhance the sensitivity and specificity of novel strategies. On the other hand, resistance to antimicrobial compounds can spread from resistant populations to susceptible ones. Antimicrobial resistance genes (ARGs) significantly disseminate AR via horizontal and vertical gene transfer. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system is a member of the bacterial immune system with the ability to remove the ARGs; therefore, it can be introduced as an effective and innovative strategy in the battle against AR. Here, we reviewed CRISPR-based bacterial diagnosis technologies. Moreover, the strategies to battle AR based on targeting bacterial chromosomes and resistance plasmids using the CRISPR-Cas system have been explained. Besides, we have presented the limitations of CRISPR delivery and potential solutions to help improve the future development of CRISPR-based platforms.

Epigenomic effects of vitamin D in colorectal cancer.

Vitamin D regulates a plethora of physiological processes in the human body and has been proposed to exert several anticancer effects. Epigenetics plays an important role in regulating vitamin D actions. In this review, we highlight the recent advances in the understanding of different epigenetic factors such as lncRNAs, miRNAs, methylation and acetylation influenced by vitamin D and its downstream targets in colorectal cancer to find more potential therapeutic targets. We discuss how vitamin D exerts anticancer properties through interactions between the vitamin D receptor and genes (e.g., SLC30A10), the microenvironment, microbiota and other factors in colorectal cancer. Developing therapeutic approaches targeting the vitamin D signaling system will be aided by a better knowledge of the epigenetic impact of vitamin D.

Vitamin D regulates various physiological processes in the body and could have anticancer effects. These anticancer effects are the result of interactions between many factors such as genes, the environment around the tumors, bacteria in the intestine, etc. in colorectal cancer. Epigenetic factors, including a big network of different molecules in the body that could control our genes without changing DNA, also play a role in regulating vitamin D. This review summarizes the advances in the understanding of different epigenetic factors related to vitamin D and colorectal cancer.

Association of MTHFR C677T variant genotype with serum folate and Vit B12 in Iranian patients with colorectal cancer or adenomatous polyps.

BACKGROUND: The incidence of colorectal cancer (CRC) has increased during recent years in Iran and other developing countries. Clinical studies suggest that essential folate dietary intake and moderate deficiency of methylenetetrahydrofolate reductase (MTHFR) may protect and reduce the risk of CRC. The present study aimed to investigate the clinical significance of C677T polymorphism within the MTHFR gene and its correlation with the serum folate and Vit B12 in the Iranian population suffering from CRC. METHODS: Blood samples were taken from 1017 Iranian individuals (517 cases and 500 controls) who were referred for colonoscopy. TaqMan probe assay was performed for C677T MTHFR polymorphism. Sera were fractionated from the blood samples of 43 patients and controls and folate and Vit B12 concentrations were measured by a monobind kit. The correlation of MTHFR polymorphisms and folate/vitamin-B12 with CRC risk was analyzed. RESULTS: In the current study, we found the frequency of three different genotypes of MTHFR polymorphism in the Iranian population i.e., CC, CT, and TT, to be 51.31, 26.73, 21.96 and 61, 32.2, 6.8 in case and control groups, respectively. The homozygote genotype of MTHFR rs1801133 polymorphism is associated with an increased risk of CRC by 3.68, 1.42, and 3.74-fold in codominant, dominant, and recessive models respectively (p value < 0.01). Our study revealed that there was no significant difference between the amount of folate and Vit B12 in the case and control groups (p value > 0.05). CONCLUSIONS: This study revealed that there was no significant difference between the amount of folate and Vit B12 in the case and control groups. Furthermore, our results demonstrated a higher risk association for 677TT and 677TT + C677T genotypes of MTHFR compared with 677CC carriers among CRC patients.

Role of aldo-keto reductase family 1 member B1 (AKR1B1) in the cancer process and its therapeutic potential.

The role of aldo-keto reductase family 1 member B1 (AKR1B1) in cancer is not totally clear but growing evidence is suggesting to have a great impact on cancer progression. AKR1B1 could participate in a complicated network of signalling pathways, proteins and miRNAs such as mir-21 mediating mechanisms like inflammatory responses, cell cycle, epithelial to mesenchymal transition, cell survival and apoptosis. AKR1B1 has been shown to be mostly overexpressed in cancer. This overexpression has been associated with inflammatory mediators including nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), cell cycle mediators such as cyclins and cyclin-dependent kinases (CDKs), survival proteins and pathways like mammalian target of rapamycin (mTOR) and protein kinase B (PKB) or AKT, and other regulatory factors in response to reactive oxygen species (ROS) and prostaglandin synthesis. In addition, inhibition of AKR1B1 has been shown to mostly have anti-cancer effects. Several studies have also suggested that AKR1B1 inhibition as an adjuvant therapy could render tumour cells more sensitive to anti-cancer therapy or alleviate the adverse effects of therapy. AKR1B1 could also be considered as a potential cancer diagnostic biomarker since its promoter has shown high levels of methylation. Although pre-clinical investigations on the role of AKR1B1 in cancer and the application of its inhibitors have shown promising results, the lack of clinical studies on AKR1B1 inhibitors has hampered the use of these drugs to treat cancer. Thus, there is a need to conduct more clinical studies on the application of AKR1B1 inhibitors as adjuvant therapy on different cancers.

The Dilemma of TP53 Codon 72 Polymorphism (rs1042522) and Breast Cancer Risk: A Case-Control Study and Meta-Analysis in The Iranian Population.

OBJECTIVE: Mutations of TP53 as a tumor suppressor gene are frequently observed in different types of cancer. A codon 72 polymorphism located on exon 4 with two alleles encoding either Proline (CCC) or Arginine (CGC) has been indicated as a common variation in association with cancers. Controversial results have been reported regarding the association of allelic polymorphism of codon 72 of TP53 gene and breast cancer risk in Iranian patients. Therefore, a case-control study was designed. A meta-analysis was also carried out to provide evidence of association between this variation and breast cancer in Iran, based on all available published data. MATERIALS AND METHODS: In this case-control study, blood sample of 622 participants, including 308 breast cancer cases and 314 controls were collected. Genotyping for rs1042522 was conducted by Allele Specific polymerase chain reaction (AS-PCR). In order to set a meta-analysis study, PubMed, Scopus and ISI Web of Knowledge and Persian databases were searched to explore relevant studies, published up to September 2018, containing information on TP53 polymorphism and the risk of breast cancer in Iran. Statistical analysis was performed using SPSS 16.0 and MetaGenyo. RESULTS: All retrieved available data as well as the results of our current study were consisted of 1965 breast cancer cases and 1999 healthy controls. No significant difference was observed in allele frequencies between groups (P=0.90) in our study. The cumulative results did not also show any association between rs1042522 and breast cancer risk on the dominant (P=0.61) and recessive (P=0.89) models. CONCLUSION: These findings cannot support contribution of rs1042522 polymorphism to breast cancer risk in an Iranian population. Future larger studies may help confirm this finding with a greater power.

Role of adenosine signaling in the pathogenesis of head and neck cancer.

The concentrations of adenosine may increase under ischemic conditions in the tumor microenvironment, and then it enters the systemic circulation. Adenosine controls cancer progression and responses to therapy by regulating angiogenesis, cell survival, apoptosis, cell proliferation, and metastases in tumors. Hence, adenosine metabolism, adenosine-generating enzymes, and adenosine signaling are potentially novel therapeutic targets in a wide range of pathological conditions, including cerebral and cardiac ischemic diseases, inflammatory disorders, immunomodulatory disorders, and, of special interest in this review, cancer. This review summarizes the role of adenosine in the pathogenesis of head and neck cancer for a better understanding of how this may be applied to treating this type of cancer.

Adenosine: An endogenous mediator in the pathogenesis of gynecological cancer.

Extracellular concentration of adenosine increases in the hypoxic tumor microenvironment. Adenosine signaling regulates apoptosis, angiogenesis, metastasis, and immune suppression in cancer cells. Adenosine-induced cell responses depend upon different subtypes of adenosine receptors activation and type of cancer. Suppression of adenosine signaling via inhibition of adenosine receptors or adenosine generating enzymes including CD39 and CD73 on ovarian or cervical cancer cells is a potentially novel therapeutic approach for gynecological cancer patients. This review summarizes the role of adenosine in the pathogenesis of gynecological cancer for a better understanding and hence a better management of this disease.