Calcium/magnesium intake ratio, but not magnesium intake, interacts with genetic polymorphism in relation to colorectal neoplasia in a two-phase study

The Role of TRPM7 in Oncogenesis

This review summarizes the current understanding of the role of transient receptor potential melastatin-subfamily member 7 (TRPM7) channels in the pathophysiology of neoplastic diseases. The TRPM family represents the largest and most diverse group in the TRP superfamily. Its subtypes are expressed in virtually all human organs playing a central role in (patho)physiological events. The TRPM7 protein (along with TRPM2 and TRPM6) is unique in that it has kinase activity in addition to the channel function. Numerous studies demonstrate the role of TRPM7 chanzyme in tumorigenesis and in other tumor hallmarks such as proliferation, migration, invasion and metastasis. Here we provide an up-to-date overview about the possible role of TRMP7 in a broad range of malignancies such as tumors of the nervous system, head and neck cancers, malignant neoplasms of the upper gastrointestinal tract, colorectal carcinoma, lung cancer, neoplasms of the urinary system, breast cancer, malignant tumors of the female reproductive organs, prostate cancer and other neoplastic pathologies. Experimental data show that the increased expression and/or function of TRPM7 are observed in most malignant tumor types. Thus, TRPM7 chanzyme may be a promising target in tumor therapy.

Ion channels and their role in chemo-resistance

Ion channels play a crucial role in cellular signaling, homeostasis, and generation of electrical and chemical signals. Aberrant expression and dysregulation of ion channels have been associated with cancer development and resistance to conventional cancer treatment such as chemotherapy. Several molecular mechanisms have been proposed to explain this phenomenon. Including evasion of apoptosis, decreased drug accumulation in cancer cells, detoxifying and activation of alternative escape pathways such as autophagy. Each of these mechanisms leads to a reduction of the therapeutic efficacy of administered drugs, causing more difficulty in cancer treatment. This review highlights the linkages between ion channels and resistance to chemotherapy. Furthermore, it elaborates their molecular mechanisms and the potential of being therapeutic targets in clinical management.

Relationships between serum and dietary magnesium, calcium, and metabolic parameters in women with type 2 diabetes mellitus

BACKGROUND & AIMS

Magnesium and calcium are essential minerals in several enzymatic activities that modulate essential biological functions. Hypomagnesemia occurs in patients with type 2 diabetes mellitus (T2DM), especially those with poor metabolic control. Dietary magnesium and calcium intake play a protective role in the development of T2DM. This research aimed to investigate the association of dietary and serum magnesium and calcium with metabolic control parameters in diabetic women.

METHODS

This case-control study was conducted on 80 women, including 40 patients diagnosed with T2DM and 40 healthy controls aged 35-60 years. Some anthropometric measurements of the individuals were taken, and their body mass index was calculated. In addition, some biochemical parameters, serum magnesium, and calcium were analyzed. A validated 96-item quantitative food frequency questionnaire was used to obtain dietary magnesium and calcium intake data.

RESULTS

Serum magnesium levels were lower in subjects with diabetes than in controls, and there was a similar incidence of hypomagnesemia in T2DM patients and controls, but not statistically significant (p > 0.05). In T2DM patients, there was a statistically significant inverse association between HbA1c and serum magnesium (p < 0.05). Dietary magnesium intake was inversely associated with HOMA-IR scores (p < 0.05) but had a positive association with serum magnesium levels in patients with T2DM (p < 0.05). There were no significant differences in the calcium/magnesium ratio between T2DM patients and healthy controls (p > 0.05). In a multiple linear regression analysis, dietary magnesium intake and HbA1c were found to be significantly related to altered serum magnesium in T2DM patients.

CONCLUSION

The present findings suggest that lower serum magnesium levels were associated with higher HbA1c levels in subjects with T2DM. Increased dietary magnesium intake in T2DM may enhance HOMA-IR scores and serum magnesium levels.

Magnesium Status and Ca/Mg Ratios in a Series of Children and Adolescents with Chronic Diseases

Magnesium (Mg) is an essential divalent cation involved in various enzymatic reactions that regulate vital biological functions. The main goal was to evaluate Mg status and its association with nutritional indicators in 78 children and adolescents with chronic diseases. We assessed anthropometric, biochemical, diet, body composition, and bone densitometry valuations. Serum Mg and Ca levels were determined using the standardized method and diet calcium (Ca) and Mg consumption by a prospective 72 h diet survey. Mean serum Ca (9.9 mg/dL), Mg (2.08 mg/dL) dietary Ca (102% DRI: Dietary Reference Intake), and Mg intake (105% DRI) were normal. A total of 45% had hypomagnesemia, 12% had hypermagnesemia, and 26% and 24% had inadequate and high Mg intake, respectively. Only 6% of patients had poor Mg intake and hypomagnesemia, and 54% and 90% of our series had an elevated serum Ca/Mg ratio > 4.70 (mean 4.79) and a low Ca/Mg intake ratio < 1.70 (mean 1.06), respectively. Both Ca/Mg ratios were linked with the risk of developing other chronic conditions such as cardiovascular disease, type 2 diabetes, syndrome metabolic, and even several cancers. Therefore, 79% of children and adolescents with chronic diseases were at elevated risk of having abnormal Mg status and developing other chronic illnesses.

Pre-diagnostic dietary consumption of calcium and magnesium and calcium-to-magnesium intake ratio and ovarian cancer mortality: results from the ovarian cancer follow-up study (OOPS)

PURPOSE

Previous studies have indicated that dietary consumption of calcium (Ca), magnesium (Mg), and the Ca-to-Mg (Ca:Mg) ratio were associated with different health outcomes. However, no study has evaluated the association of pre-diagnostic Ca, Mg, and Ca:Mg ratio consumption with ovarian cancer (OC) survival.

METHODS

The aforementioned associations were investigated in a cohort of 853 Chinese women diagnosed with OC between 2015 and 2020. A validated food frequency questionnaire was used to evaluate pre-diagnostic diet information. Deaths were recorded until March 31, 2021 via medical records and active follow-up. Cox proportional hazards model was applied to calculate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 130 deaths were observed during a median follow-up of 37.2 months. After adjustment for potential confounders, pre-diagnostic Ca (HR_{< 600 vs. > 1000} = 1.45, 95% CI = 0.47-4.46, p for trend = 0.69) and Mg (HR_{< 250 vs. > 330} = 0.90, 95% CI = 0.39-2.08, p for trend = 0.77) intakes were found to be unrelated to OC survival, whereas a higher Ca:Mg intake ratio was significantly associated with worse survival (HR_{< 1.7 vs. > 2.5} = 2.72, 95% CI = 1.28-5.78, p for trend < 0.05). A significant result was also observed when treating the Ca:Mg ratio as a continuous variable (HR = 1.69, 95% CI = 1.12-2.55) for one-unit increment.

CONCLUSION

Pre-diagnostic consumption of Ca and Mg was unrelated to OC survival, while a higher Ca:Mg intake ratio was strongly associated with worse survival among OC patients.

Associations between calcium and magnesium intake and the risk of incident oesophageal cancer: an analysis of the NIH-AARP Diet and Health Study prospective cohort

BACKGROUND

Risk reduction through dietary modifications is an adjunct strategy for prevention of oesophageal cancer, a leading cause of cancer-related mortality and morbidity worldwide. We aimed to estimate the association between calcium and magnesium intakes and incident oesophageal cancer (OC).

METHODS

We conducted a retrospective analysis of the NIH-AARP Diet and Health Study prospective cohort. We used multivariable Cox proportional hazard modeling to estimate the association between total intakes and incident OC overall and by histology (oesophageal squamous cell carcinoma (OSCC) and adenocarcinoma (OAC)). Sensitivity and stratified analyses were performed.

RESULTS

Among 536,359 included respondents, 1414 incident OCs occurred over 6.5 million person-years follow-up time. Increasing dietary calcium intake was associated with an adjusted 32-41% lower risk of OSCC compared to the lowest quartile (p-trend 0.01). There was a positive association between increasing magnesium intake and OAC risk, but only among participants with low calcium:magnesium intake ratios (p-trend 0.04). There was a significant interaction with smoking status.

CONCLUSIONS

Based on a retrospective analysis of the NIH-AARP Diet and Health Study prospective cohort, dietary intakes of calcium and magnesium were significantly associated with risk of OSCC and, among certain participants, OAC, respectively. If validated, these findings could inform dietary modifications among at-risk individuals. Mechanistic investigations would provide additional insight.

Additively protective effects of vitamin D and calcium against colorectal adenoma incidence, malignant transformation and progression: A systematic review and meta-analysis

BACKGROUND

Colorectal cancer (CRC) exhibits a linear progression from normal colonic epithelium, adenoma initiation, carcinoma transformation and even to metastasis. Diet changes might influence carcinogenesis and prognosis. We aimed to determine the effects of vitamin D and calcium on colorectal adenoma incidence, malignancy development and prognosis.

METHODS

Systematic literature searches (PubMed, Embase, and Cochrane Library databases) and hand searches were performed by September 30, 2019. A random-effects model was adopted to pool relative ratios (RRs) for colorectal tumour incidence or hazard ratios (HRs) for CRC mortality. Stratified analyses were performed by gender, tumour location, calcium intake level and ethnic group.

RESULTS

Total 854,195 cases from 166 studies were included. The colorectal adenoma incidence was inversely correlated with the circulating 25-hydroxyvitamin D [25(OH)D] level (RR: 0.80, 95% CI: 0.71-0.89), vitamin D intake (RR: 0.87, 95% CI: 0.82-0.92) and calcium intake (RR: 0.86, 95% CI: 0.81-0.91). The CRC incidence was decreased by circulating 25(OH)D (RR: 0.67, 95% CI: 0.59-0.77), vitamin D intake (RR: 0.85, 95% CI: 0.78-0.93) and calcium intake (RR: 0.75, 95% CI: 0.70-0.79). High-level circulating 25(OH)D triggered better overall survival (HR: 0.67, 95% CI: 0.57-0.79) and CRC-specific survival (HR: 0.63, 95% CI: 0.53-0.74). Stratified analyses showed that vitamin D and calcium significantly suppressed colorectal tumour incidence among women. Left-sided CRC risk was reversely related to circulating 25(OH)D (RR: 0.60, 95% CI: 0.41-0.88) and vitamin D intake (RR: 0.73, 95% CI: 0.57-0.93). Circulating 25(OH)D decreased colorectal adenoma (RR: 0.63, 95% CI: 0.48-0.82) and CRC (RR: 0.69, 95% CI: 0.56-0.86) risk in populations with higher calcium intake. European and American populations benefited more from vitamin D intake against colorectal tumour. A significant dose-response relationship was observed between intake of vitamin D or calcium and colorectal tumour incidence.

CONCLUSIONS

Vitamin D and calcium play additively chemopreventive roles in colorectal adenoma incidence, malignant transformation and progression, especially for women and left-sided CRC patients.

Associations between calcium and magnesium intake and the risk of incident gastric cancer: A prospective cohort analysis of the National Institutes of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study

Gastric cancer remains a leading cause of cancer-related mortality. Identifying dietary and other modifiable disease determinants has important implications for risk attenuation in susceptible individuals. Our primary aim was to estimate the association between dietary and supplemental intakes of calcium and magnesium and the risk of incident gastric cancer. We conducted a prospective cohort analysis of the National Institutes of Health-American Association of Retired Persons Diet and Health Study. We used Cox proportional hazard modeling to estimate the association between calcium and magnesium intakes with risk of incident gastric adenocarcinoma (GA) overall and by anatomic location, noncardia GA (NCGA) and cardia GA (CGA). A total of 536,403 respondents (59% males, 41% females) were included for analysis, among whom 1,518 incident GAs (797 NCGA and 721 CGA) occurred. Increasing calcium intake was associated with lower risk of GA overall (p-trend = 0.05), driven primarily by the association with NCGA, where the above median calcium intakes were associated with a 23% reduction in risk compared to the lowest quartile (p-trend = 0.05). This magnitude of NCGA risk reduction was greater among nonwhite ethnic group and Hispanics (hazard ratio [HR] 0.51, 95% confidence interval [CI]: 0.24-1.07, p-trend = 0.04), current/former smokers (HR 0.58, 95% CI: 0.41-0.81), obese individuals (HR 0.54, 95% CI: 0.31-0.96) and those with high NCGA risk scores (HR 0.50, 95% CI: 0.31-0.80). Among men only, increasing magnesium intake was associated with 22-27% reduced risk of NCGA (p-trend = 0.05), while for the cohort, dietary magnesium intake in the highest vs. lowest quartile was associated with a 34% reduced risk of NCGA (HR 0.66, 95% CI: 0.48-0.90). These findings have important implications for risk factor modification. Future investigations are needed not only to confirm our results, but to define mechanisms underlying these associations.

Ion Channels: New Actors Playing in Chemotherapeutic Resistance

In the battle against cancer cells, therapeutic modalities are drastically limited by intrinsic or acquired drug resistance. Resistance to therapy is not only common, but expected: if systemic agents used for cancer treatment are usually active at the beginning of therapy (i.e., 90% of primary breast cancers and 50% of metastases), about 30% of patients with early-stage breast cancer will have recurrent disease. Altered expression of ion channels is now considered as one of the hallmarks of cancer, and several ion channels have been linked to cancer cell resistance. While ion channels have been associated with cell death, apoptosis and even chemoresistance since the late 80s, the molecular mechanisms linking ion channel expression and/or function with chemotherapy have mostly emerged in the last ten years. In this review, we will highlight the relationships between ion channels and resistance to chemotherapy, with a special emphasis on the underlying molecular mechanisms.

Genetic variation in SLC7A2 interacts with calcium and magnesium intakes in modulating the risk of colorectal polyps

Solute carrier family 7, member 2 (SLC7A2) gene encodes a protein called cationic amino acid transporter 2, which mediates the transport of arginine, lysine and ornithine. l-Arginine is necessary for cancer development and progression, including an important role in colorectal cancer pathogenesis. Furthermore, previous studies found that both calcium and magnesium inhibit the transport of arginine. Thus, calcium, magnesium or calcium:magnesium intake ratio may interact with polymorphisms in the SLC7A2 gene in association with colorectal cancer. We conducted a two-phase case-control study within the Tennessee Colorectal Polyps Study. In the first phase, 23 tagging single-nucleotide polymorphisms in the SLC7A2 gene were included for 725 colorectal adenoma cases and 755 controls. In the second phase conducted in an independent set of 607 cases and 2113 controls, we replicated the significant findings in the first phase. We observed that rs2720574 significantly interacted with calcium:magnesium intake ratio in association with odds of adenoma, particularly multiple/advanced adenoma. In the combined analysis, among those with a calcium:magnesium intake ratio below 2.78, individuals who carried GC/CC genotypes demonstrated higher odds of adenoma [OR (95% CI):1.36 (1.11-1.68)] and multiple/advanced adenoma [OR (95% CI): 1.68 (1.28, 2.20)] than those who carried the GG genotype. The P values for interactions between calcium:magnesium intake ratio and rs2720574 were .002 for all adenomas and <.001 for multiple/advanced adenoma. Among those with the GG genotype, a high calcium:magnesium ratio was associated with increased odds of colorectal adenoma [OR (95% CI): 1.73 (1.27-2.36)] and advanced/multiple adenomas [1.62 (1.05-2.50)], whereas among those with the GC/CC genotypes, high calcium:magnesium ratio was related to reduced odds of colorectal adenoma [0.64 (0.42-0.99)] and advanced/multiple adenomas [0.55 (0.31-1.00)].