Genetic Variants in the Mitochondrial Thymidylate Biosynthesis Pathway Increase Colorectal Cancer Risk.

We assess the contributions of genetic variants for the enzymes involved in capecitabine metabolism to colorectal cancer (CRC) development risk. In this case-control study, DNA samples were collected from 66 patients (King Abdulaziz University Hospital) and 65 controls (King Fahad General Hospital) between April and November 2022 to be used in PCR-RFLP. The chi-square (χ2) test at a significance level of p ˂ 0.05 was used to estimate genotype and allele frequencies. The Lys27Gln variant of cytidine deaminase (CDA) showed a risk ratio (RR) of 1.47 for heterozygous (AC) carriers, with genotype distributions for patients (χ2 = 1.97) and controls (χ2 = 14.7). Homozygous (AA) Ala70Thr carriers demonstrated a three-fold higher risk, with genotype distributions for patients (χ2 = 3.85) and controls (χ2 = 4.23). Genotype distributions of the 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T variant for patients were (χ2 = 22.43) and for controls were (χ2 = 0.07); for the MTHFR A1298C variant, they were (χ2 = 54.44) for patients and (χ2 = 4.58) for controls. Heterozygous (AC) carriers of the A1298C variant demonstrated highly significant protection against CRC development (RR = 0.2, p = 0.001), while a two-fold higher risk for CRC was estimated for homozygous genotype (CC) carriers. In conclusion, the heterozygous genotype of CDA Lys27Gln, the homozygous genotype of CDA Ala70Thr, and the homozygous genotype of MTHFR A1298C were associated with CRC development risk. The heterozygous genotype of MTHFR A1298C variant provided highly significant protection against CRC development. Further examinations using a larger population size are needed to reliably confirm our findings.

5­Fluorouracil and capecitabine therapies for the treatment of colorectal cancer (Review).

Although 5­fluorouracil (5­FU)­based chemotherapy is the major treatment for colorectal cancer, it has disadvantages such as systemic toxicity, lack of effectiveness and selectivity, and development of resistance. Capecitabine, a prodrug form of 5­FU, was designed to overcome these drawbacks, to fulfill the need for more convenient therapy, and to improve safety, tolerability and intratumor drug concentration levels through a tumor­specific conversion to the active 5­FU drug. The purpose of the present review is to provide a comprehensive comparison between 5­FU therapy and capecitabine. In the current review, anticancer drug classification was discussed and the development of capecitabine from the original fluorinated analogue (5­FU) to overcome its drawbacks was explained. Specifically, 5­FU is compared with capecitabine therapy regarding various properties, including drug metabolism, cellular mechanism, effect on the apoptosis pathway and cell cycle phases, safety and tolerability. Moreover, three metabolizing enzymes required for the activation of capecitabine to 5­FU were discussed. Capecitabine, as monotherapy or in combination with other chemotherapies, exhibited improved drug efficacy and survival. However, the changes that mediate the chemoresistance of capecitabine treatment were classified as intracellular, extracellular or cell surface factors, or cell­phenotype state. Future studies should examine the efficacy of capecitabine combined with novel and safe drugs other than chemotherapeutic agents that play a role in the inhibition of tumor initiation, progression and metastasis.

Biochemical and histological effects of five weeks ingestion of Zamzam water on the liver and kidneys of Wistar rats.

Zamzam water is a natural alkaline water which has become alkaline as a result of the natural environment. It comes from what is considered as one of the oldest springs in the world. The water contains high concentrations of alkaline minerals as well as trace and heavy metals. The aim of the current study is to evaluate the effects of five weeks ingestion of Zamzam water on the liver and kidney functions of rats. Adult female Wistar rats weighing 150-200 g were divided into two groups, with 15 rats in each. The control group was supplied daily by bottled water and the Zamzam water group was supplied daily by 500 ml of Zamzam water for five weeks. The rats were weighed weekly and, at the end of the experiment, blood samples were collected from all rats for the biochemical determination of serum levels of aspartate transaminase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, creatinine, albumin, and uric acid, using calorimetric methods. Liver and kidney tissues were fixed in 10% neutral buffered-formalin solution and further embedded in wax blocks for routine hematoxylin and eosin (H&E) staining and were examined for histopathological changes using a light microscope. The results of the current study showed that there was a significant increase (P < 0.05) in the weight of the Zamzam group when compared to the control group after five weeks of ingestion. Liver and kidney function tests did not show any significant difference when compared with the controls (P > 0.05). In addition, histological examination of the liver and kidney tissues did not show any toxicological changes. In conclusion, the results showed that the ingestion of Zamzam water did not alter serum levels of kidney function tests and liver enzymes; and did not result in a noticeable change in the liver and kidney histology. Thus, the high concentrations of elements in Zamzam water do not induce hepatotoxicity or nephrotoxicity and the water is considered safe for long-term consumption.

Association between MDR1 polymorphisms and XELIRI and XELOX chemoresistance in Saudi patients with colorectal cancer.

Multidrug resistance member 1 (MDR1) is located on chromosome 7 and encodes P-glycoprotein, which is universally accepted as a drug resistance biomarker. MDR1 polymorphisms can alter protein expression or function, which has been previously reported to associate with various types of malignancies, such as colorectal cancer (CRC). Therefore, the present study aimed to determine the effects of MDR1 polymorphisms on drug responses of Saudi patients with CRC. DNA samples were obtained from 62 patients with CRC and 100 healthy controls. Genotypes and allele frequencies of MDR1 single nucleotide polymorphisms (SNPs) G2677T and T1236C were determined using the PCR-restriction fragment length polymorphism procedure. The results showed no significant differences in the genotype distribution and allele frequency of T1236C between patients with CRC and controls. However, G2677T was found to serve a highly significant role in protecting against the progression of CRC. In addition, none of the genotypes in SNPs T1236C and G2677T was found to affect chemoresistance to XELIRI and XELOX. In conclusion, although T1236C in the MDR1 gene is not associated with CRC risk, G2677T protects against the development of CRC. Neither of the MDR1 SNPs tested were associated with the risk of chemoresistance. Therefore, these two SNPs cannot be used as molecular markers for predicting drug response in patients with CRC.

TaqI and ApaI Variants of Vitamin D Receptor Gene Increase the Risk of Colorectal Cancer in a Saudi Population.

BACKGROUND: Polymorphisms in the gene encoding the vitamin D receptor (VDR) affect the protective role of vitamin D against many types of cancers, including colorectal cancer (CRC). OBJECTIVE: The objective of this study was to assess the effect of four major polymorphisms of the VDR gene (ApaI, TaqI, BsmI and FokI) on the risk of CRC in a Saudi population. MATERIALS AND METHODS: This case-control study recruited 132 CRC patients from the oncology clinics at King Abdulaziz University Hospital and 124 healthy controls from the blood bank at King Fahad General Hospital, Jeddah, Saudi Arabia, between September 2017 and August 2018. All participants were Saudis and aged 20-80 years. Genomic DNA samples were extracted from the peripheral blood cells and amplified with polymerase chain reaction. The resulting fragments were digested with different endonucleases to reveal the genotypes using the restriction fragment length polymorphism technique. The genotype distribution and allele frequency, odds ratio (OR), risk ratio (RR) and P values were determined with contingency table analysis following Hardy-Weinberg equilibrium equation. RESULTS: For the ApaI single-nucleotide polymorphism (SNP) (rs7975232), only the heterozygous (Aa) genotype increased the risk of CRC (OR = 3.4, RR = 2.3, and P < 0.0001), whereas the TaqI SNP (rs731236) carriers with either the heterozygous (Tt) or homozygous (tt) genotype displayed an increased risk for the disease (OR = 6.18, RR = 4, P < 0.0001; OR = 3, RR = 2.4, P = 0.02, respectively). In contrast, heterozygous (Bb) and homozygous (bb) carriers of the BsmI SNP (rs1544410) had significantly lower risk for CRC (P < 0.0001). Finally, for the FokI SNP (rs2228570), there was no association with CRC risk. CONCLUSION: This study found that VDR SNPs ApaI and TaqI increase the risk of CRC, whereas BsmI reduces the risk of CRC in the selected Saudi population. Therefore, ApaI and TaqI SNPs could potentially be used as a diagnostic biomarker for CRC. However, the molecular mechanisms by which these variants increase or decrease the risk of CRC need to be investigated.

Increased expressions of cellular ATP-binding cassette transporters may be a promising diagnostic marker for colorectal cancer.

OBJECTIVES: To measure the blood expression levels of related drug-resistant ATP-binding cassette (ABC) transporters in colorectal cancer (CRC) patients and to assess these examined transporters for whether they present signi cant expression in connection with the tumor appearance of CRC. METHODS: In this case-control study, the messenger ribonucleic acids were isolated from the blood of 62 CRC patients who were recruited from King Abdulaziz University Hospital Oncology Clinic and 46 controls from King Fahad General Hospital Blood Bank (Jeddah, Saudi Arabia) from September 2016 to March 2017. The Biomedical Ethics Unit at King Abdulaziz University, Jeddah, Saudi Arabia approved this study. The expressions of ABC transporters were measured using quantitative polymerase chain reaction. GraphPad Prism 5 and REST 2009 Software were used to correlate the expressions with clinicopathological independent stages and body mass index. A p-value of less than 0.05 was considered significant. RESULTS: The results showed that the 3 ABC transporters, particularly ABCC1 (p less than 0.0001), were highly expressed in the blood of CRC patients compared with controls. However, none of the 3 transporters was related to the progression of CRC, age, gender, or body mass index. CONCLUSION: The expressions of ABC transporters were found to be significantly higher in CRC patients, and they may act as diagnostic markers and should potentially be tested for their contribution to drug sensitivity in CRC patients.

Serum visfatin concentration and its relationship with sex hormones in obese Saudi women.

Objective: Visfatin is an adipokine secreted mainly by adipose tissue and has been implicated in obesity. It also mimics the effects of insulin and its expression is hormonally regulated by hormones. Serum visfatin concentrations were evaluated in Saudi women of different body weights to determine its relationships with sex hormones and obesity-induced insulin resistance (IR) in women in Saudi Arabia. Methods: In this cross-sectional study, 83 healthy Saudi women of different body weights were recruited between 2014 and 2016, from King Abdulaziz University staff and students. They were divided into three groups according to their body mass indexes (BMIs). Anthropometric measurements were recorded for all of the participants. Blood samples were collected to assess the biochemical variables, including glucose, insulin, lipid profile, visfatin, sex hormone-binding globulin (SHBG), and sex hormones levels. Results: Obese women exhibited significantly higher blood pressure (BP), glucose, insulin, IR, lipid profile, and visfatin levels than overweight and lean women. However, lean women had significantly higher high-density lipoprotein-cholesterol (HDL)-C, estradiol (E2), luteinizing hormone (LH), and SHBG levels than overweight and obese women. Positive correlations were observed between visfatin levels and waist and hip circumferences, BMI, diastolic BP, systolic BP (SBP) insulin, IR, and LDL-C levels (P < 0.001 - P < 0.05). Negative correlations were observed between visfatin levels and HDL-C, SHBG, LH, and E2 levels (P < 0.001 - P < 0.05). Conclusions: The results of this study revealed that E2 and SHBG concentrations were decreased in obese women, while visfatin levels were increased in obese women with high IR levels. This suggests that visfatin levels and sex hormones interact synergistically with obesity with regard to the IR risk in obese women.

Serum vitamin D receptor (VDR) levels as a potential diagnostic marker for colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity worldwide, and there has been a significant increase in the incidence of CRC in recent decades. Therefore, there is an urgent need to identify blood biomarkers that can be used for early diagnosis. It is not yet clear whether the level of vitamin D and its receptor, vitamin D receptor (VDR), in the blood are helpful factors in the diagnosis of CRC. Therefore, the study focuses on determining the VDR serum level's contribution and other chemical parameters to the risk of CRC. A total of 189 Saudi participants (66 CRC patients and 123 control patients) aged 20-80 years old were enrolled in this case-control study. A serum sample was collected from each participant, and the levels of VDR and other bone profile tests were determined using ELISA or chemiluminescent assays. P values < 0.05 were considered statistically significant. The results showed a highly significant reduction in the levels of total vitamin D (P < 0.0001), VDR (P < 0.0001), vitamin D3 (P < 0.05), and calcium (P < 0.0001) in the serum of CRC patients compared to the controls. However, the alkaline phosphatase level was higher in CRC patients compared to the controls (P < 0.0001). None of the blood markers showed a significant correlation to the progression of CRC (P > 0.05). More investigation is needed to elucidate different physiological processes that can be affected by these blood biomarkers, therefore changing the carcinogenesis of CRC.

Antiproliferative and apoptotic effects of the natural alkaline water (Zamzam) in breast cancer cell line MCF-7.

BACKGROUND: Zamzam water (ZW) is a natural alkaline water that contains several minerals that may represent a powerful tool for cancer therapy. OBJECTIVES: In this research, in vitro antiproliferative and apoptotic effects of ZW were investigated in the human breast cancer cell line MCF-7. MATERIALS AND METHODS: This study was conducted between January 2015 and February 2016. The effects of ZW on the morphology and the cell viability of human breast cancer cell line MCF-7 were determined. The cell death type and cell cycle changes were investigated using flow cytometry. Finally, reactive oxygen species (ROS) were also measured by fluorometric technique. RESULTS: MCF-7 cells treated with either ZW with adjusted pH at 7.2 or unadjusted pH at 8 showed reduced cell viability of cancerous cells. The cell death occurred through the apoptosis pathway under both treatment conditions. The treated MCF-7 cells were arrested in the G2/M phase and decreased in the G1 phase. Only the unadjusted pH ZW sample demonstrated an increase in the production of both cytoplasmic and mitochondrial ROS in MCF-7 cells. CONCLUSION: All the results in the present study indicated, for the first time, that ZW might have anticancer and apoptotic effects on breast cancer cell line.

Relationship between Serum Vitamin D and Calcium Levels and Vitamin D Receptor Gene Polymorphisms in Colorectal Cancer.

BACKGROUND: Many epidemiological studies have shown that vitamin D deficiency is associated with various types of human cancers. The biological action of vitamin D and its metabolites is mediated by the transcription factor vitamin D receptor (VDR). The VDR gene is highly expressed in the colon and is involved in many biological functions. The aim of the current study was to assess the relationship between serum vitamin D metabolite and calcium levels with VDR polymorphisms in normal and colorectal cancer (CRC) patients. METHODS: Fifty Saudi CRC patients and fifty controls were enrolled in the study. The levels of total vitamin D, 25(OH)D3, and calcium were measured in serum. RESULTS: The homozygous genotype (aa) of the ApaI VDR polymorphism (rs7975232) was found to correlate with total serum vitamin D levels of CRC patients, while the heterozygous (Tt) TaqI VDR polymorphism (rs731236) was associated with serum calcium levels. In contrast, the BsmI and FokI VDR polymorphisms (rs1544410 and rs2228570, resp.) did not affect the serum levels of total vitamin D, 25-hydroxyvitamin D3, and calcium. CONCLUSION: Appropriate vitamin D levels were shown to be important in preventing the onset of CRC.

Insulin resistance and its correlation with chemerin and visfatin in Saudi patients with hyperthyroidism.

Objective: This study aimed to assess the relationship between chemerin and visfatin concentrations and insulin resistance in Saudi women with hyperthyroidism. Materials and Methods: Seventy healthy participants and 70 participants with hyperthyroidism were recruited for the study. Concentrations of chemerin, visfatin, thyroid profile, fasting glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) were measured. Results: Hyperthyroid patients showed significantly higher concentrations of fasting glucose and insulin (P < 0.001) and significant increases in HOMA-IR values than the control group. Spearman's correlation coefficient analysis showed that thyroid-stimulating hormone was negatively correlated with glucose, insulin, and HOMA-IR, while free triiodothyronine was positively correlated with the same parameters. Total triiodothyronine and total thyroxine also showed a significant positive correlation with glucose, and the levels of thyroglobulin were also positively correlated with insulin and HOMA-IR. Furthermore, chemerin levels correlated positively with glucose, insulin, and HOMA-IR. Inversely, visfatin was negatively correlated with insulin and HOMA-IR. Conclusion: A significant relationship was observed between adipokines and thyroid profile, glucose, insulin, and insulin resistance in hyperthyroid patients. This suggests that visfatin and chemerin levels might affect insulin sensitivity in conjunction with thyroid hormones and thus may alter the metabolism of glucose and leads to insulin resistance.

The potential influence of hyperthyroidism on circulating adipokines chemerin, visfatin, and omentin.

Objectives: The aim of this study was to investigate the potential influence of hyperthyroidism on serum chemerin, visfatin, and omentin concentrations. The relationship between these adipokines and thyroid profile values was also investigated. Methods: A total of 140 female Saudi participants aged 20-45 years were recruited and divided into two groups, the euthyroid control group (n = 70) and the hyperthyroidism group (n = 70). Chemerin, visfatin, omentin, and thyroid profile including thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3), total thyroxine (TT4), and thyroglobulin were measured for all participants. Results: Serum chemerin levels were significantly higher in patients with hyperthyroidism compared to the controls. In contrast, serum visfatin and omentin concentrations were significantly lower in hyperthyroid patients than controls. Moreover, serum chemerin concentrations were positively correlated with TT3, TT4, and FT3 and negatively correlated with TSH and FT4. A negative correlation was also found between FT4 and TT4 and serum visfatin concentrations. Inversely, TSH correlated positively with serum visfatin levels. No significant correlation was observed between serum omentin concentrations and any of the thyroid profile variables except FT3. Conclusion: Hyperthyroidism influences serum chemerin, visfatin, and omentin concentrations, and these adipokines are correlated with thyroid hormones.

Novel association between heterozygous genotype of single nucleotide polymorphism C218T in drug transporter ABCC1 gene and increased risk of colon cancer.

OBJECTIVES: To determine the role of G128C and C218T variants in ABCC1 gene with the risk of developing colon cancer in Jeddah, Kingdom of Saudi Arabia. Methods: This case-control study was conducted on 51 colon cancer patients and 65 controls from King Abdulaziz University Hospital and King Abdullah Medical City in the period from January 2015 to April 2017, and was approved by the Unit of Biomedical Ethics (no: 261-15). Experiments were performed in the experimental biochemistry unit at King Fahd Medical Research Center. The genotype distributions and allele frequencies were determined by polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) and DNA sequencing. A Chi-square test was used to determine allele and genotype distributions, odds ratio (OR), risk ratio (RR) and 95% confidence intervals (CI). P-values of less than 0.05 were considered statistically significant. Results: The results showed a novel association between heterozygous (CT) genotype for variant C218T and increased risk of colon cancer [OR=3.4, 95% CI (1.56-7.48), and RR=1.92, 95% CI (1.26-2.93), p=0.002]. These ratios were correlated with high-grade stages (III and IV). In contrast, for variant G128C, there was no significant association with the risk of developing colon cancer. Conclusion: The novel findings of the study revealed that the CT genotype of variant C218T in ABCC1 gene may increase the risk of developing colon cancer.

ABCB1 variants C3435T and T129C are not associated with colorectal cancer risk.

BACKGROUND: Colorectal cancer (CRC) is one of the most prevalent cancers in Saudi Arabia that is highly characterized with poor survival rate and advanced metastasis. Many studies contribute this poor outcome to the expression of ABC transporters on the surface of cancer cells. OBJECTIVES: In this study, two ABCB1 variants, C3435T and T129C, were examined to evaluate their contribution to CRC risk. METHODS: 125 subjects (62 CRC patients and 63 healthy controls) were involved. The DNA was isolated and analyzed with PCR-RFLP to determine the different genotypes. The hardy-Weinberg equilibrium was performed to determine genotype distribution and allele frequencies. Fisher's exact test (two-tailed) was used to compare allele frequencies between patients and control subjects. RESULTS: The study showed that for SNP C3435T, the population of both CRC patients and controls were out of Hardy-Weinberg equilibrium. Genotype distribution for CRC patients was (Goodness of fit χ2 = 20, df= 1, P≤0.05), whereas, for the controls the genotype distribution was (Goodness of fit χ2 = 21, df =1, P ≤0.05). For SNP T129C, all subjects showed normal (TT) genotype. CONCLUSION: There was no significant association between ABCB1 3435C>T and 129T>C polymorphisms with CRC risk.

In Vitro Cytotoxic and Anticancer Effects of Zamzam Water in Human Lung Cancer (A594) Cell Line.

BACKGROUND: Zamzam water is naturally alkaline and rich in a variety of minerals which may represent a powerful tool for cancer therapy. In this research, the cytotoxic effects of Zamzam water were investigated in human lung cancer (A549) cell line and compared with human skin fibroblasts (HSF). METHODS: Two different preparations of Zamzam water were used: Z1, with pH adjusted to 7.2 and Z2, with no pH adjustment. The effects of both treatments on the morphology of the A549 and HSF cell lines were investigated. The cell viability of HSF and A549 cells was identified by the MTT assay and trypan blue exclusion. Detection of apoptotic cells and cell cycle analyses were determined using flow cytometry. Moreover, reactive oxygen species (ROS) were measured for both cell lines. RESULTS: Both Zamzam water treatments, Z1 and Z2 showed reductions in the cell viability of A549 cells. Cell death occurred via necrosis among cells treated with Z2. Cell cycle arrest occurred in the G0/G1 phases for cells treated with Z2. Cellular and mitochondrial ROS productions were not affected by either treatment. CONCLUSION: Our findings indicate that Zamzam water might have potential therapeutic efficacy for lung cancer.

Diversity, Physiochemical and Phylogenetic Analyses of Bacteria Isolated from Various Drinking Water Sources.

OBJECTIVE: To evaluate the indigenous bacterial strains of drinking water from the most commercial water types including bottled and filtered water that are currently used in Saudi Arabia. METHODS: Thirty randomly selected commercial brands of bottled water were purchased from Saudi local markets. Moreover, samples from tap water and filtered water were collected in sterilized glass bottles and stored at 4°C. Biochemical analyses including pH, temperature, lactose fermentation test (LAC), indole test (IND), methyl red test (MR), Voges-Proskauer test (VP), urease test (URE), catalase test (CAT), aerobic and anaerobic test (Ae/An) were measured. Molecular identification and comparative sequence analyses were done by full length 16S rRNA gene sequences using gene bank databases and phylogenetic trees were constructed to see the closely related similarity index between bacterial strains. RESULTS: Among 30 water samples tested, 18 were found positive for bacterial growth. Molecular identification of four selected bacterial strains indicated the alarming presence of pathogenic bacteria Bacillus spp. in most common commercial types of drinking water used in Saudi Arabia. CONCLUSION: The lack of awareness about good sanitation, poor personal hygienic practices and failure of safe water management and supply are the important factors for poor drinking water quality in these sources, need to be addressed.