Changes in intracellular folate metabolism during high-dose methotrexate and Leucovorin rescue therapy in children with acute lymphoblastic leukemia

Targeting the sulfur-containing amino acid pathway in leukemia

sulfur-containing amino acids have been reported to patriciate in gene regulation, DNA methylation, protein synthesis and other physiological or pathological processes. In recent years, metabolism-related molecules of sulfur-containing amino acids affecting the occurrence, development and treatment of tumors have been implicated in various disorders, especially in leukemia. Here, we summarize current knowledge on the sulfur-containing amino acid metabolism pathway in leukemia and examine ongoing efforts to target this pathway, including treatment strategies targeting (a) sulfur-containing amino acids, (b) metabolites of sulfur-containing amino acids, and (c) enzymes and cofactors related to sulfur-containing amino acid metabolism in leukemia. Future leukemia therapy will likely involve innovative strategies targeting the sulfur-containing amino acid metabolism pathway.

Metabolomic profiling reveals the mechanisms underlying the nephrotoxicity of methotrexate in children with acute lymphoblastic leukemia

BACKGROUND

Methotrexate is widely recommended as a first-line treatment for the intensive systemic and consolidation phases of childhood acute lymphoblastic leukemia. However, methotrexate-induced nephrotoxicity is a severe adverse reaction, of which the mechanisms remain unclear.

METHODS

An untargeted metabolomics analysis of serum from childhood acute lymphoblastic leukemia patients with delayed methotrexate excretion, with or without acute kidney injury, was performed to identify altered metabolites and metabolic pathways. An independent external validation cohort and in vitro HK-2 cell assays further verified the candidate metabolites, and explored the mechanisms underlying the nephrotoxicity of methotrexate.

RESULTS

Four metabolites showed significant differences between normal excretion and delayed excretion, seven metabolites reflected the differences between groups with or without acute kidney injury, and six pathways were finally enriched. In particular, oxidized glutathione was confirmed as a candidate metabolite involved in the toxicity of methotrexate. We further explored the role of glutathione deprivation-induced ferroptosis on methotrexate cytotoxicity, and it was found that methotrexate overload significantly reduced cell viability, triggered reactive oxygen species and intracellular Fe2+ accumulation, and altered the expression of ferroptosis-related proteins in HK-2 cells. These methotrexate-induced changes were alleviated or reversed by the administration of a ferroptosis inhibitor, further suggesting that ferroptosis promoted methotrexate-induced cytotoxicity in HK-2 cells.

CONCLUSIONS

Our findings revealed complex metabolomic profiles and provided novel insights into the mechanism by which ferroptosis contributes to the nephrotoxic effects of methotrexate.

Protective effect of cryotherapy against oral mucositis among allogeneic hematopoietic stem cell transplant recipients using melphalan-based conditioning

PURPOSE

Oral cryotherapy is an effective method to prevent oral mucositis (OM) induced by chemotherapeutic agents, such as melphalan (Mel). However, there is limited data about cryotherapy in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients; thus, the current study aimed to examine the efficacy of cryotherapy among allo-HSCT recipients treated with Mel-containing regimens.

METHODS

Medical records of 78 consecutive allo-HSCT recipients were retrospectively analyzed. Baseline characteristics and clinical courses between the patients who received cryotherapy (cryotherapy group, n = 42) and those who did not (control group, n = 36) were compared, especially focusing on methotrexate (MTX) use as a part of graft-versus-host disease (GVHD) prophylaxis.

RESULTS

Binary logistic regression analysis revealed that a higher dose of Mel (OR, 3.82; 95%CI, 1.085-13.46; P = 0.037) or MTX use (OR, 7.61; 95% CI, 2.41-23.97; P < 0.001) was associated with the incidence of OM. MTX use was also significantly associated with the duration of OM (β = 0.515; 95% CI, 9.712-21.636; P < 0.001). Among 31 patients without MTX use, cryotherapy was associated with a significant reduction of OM development (0% in the cryotherapy group vs 35% in the control group, P = 0.021). We did not find such an association in 47 patients with MTX use.

CONCLUSION

Cryotherapy was useful to prevent the incidence of OM in allo-HSCT recipients in the cases without MTX for GVHD prophylaxis.

Folate, folic acid, and chemotherapy-induced toxicities: a systematic literature review

Folate metabolism is a target for various chemotherapeutic drugs. Folate and its synthetic variant folic acid are B-vitamins. To what extent these vitamins impact treatment tolerance in patients with cancer remains unclear. A systematic literature review was conducted on intake and status of folate and folic acid in relation to chemotherapy-induced toxicities in children and adults with cancer. A total of 6,231 publications were identified, of which 40 publications met the inclusion criteria. In 12 out of 22 studies focusing on antifolates, a deficient folate status and lower folate and folic acid intake were associated with a higher risk of toxicities. In 8 out of 14 studies focusing on fluoropyrimidine treatments, a higher folate status and intake were associated with a higher risk of toxicities. These findings might explain interindividual differences in treatment tolerance and highlight the importance of evaluating nutritional status in oncology care.

Nutritional Approaches to Modulate Cardiovascular Disease Risk in Systemic Lupus Erythematosus: A Literature Review

Systemic lupus erythematosus (SLE) is a chronic pathology characterized by a bimodal mortality pattern attributed to clinical disease activity and cardiovascular disease (CVD). A complex interaction between traditional CVD risk factors such as obesity, dyslipidemia, smoking, insulin resistance, metabolic syndrome, and hypertension, as well as the presence of non-traditional CVD risk factors such as hyperhomocysteinemia, pro-inflammatory cytokines, and C-reactive protein levels, has been suggested as a cause of the high prevalence of CVD in SLE patients. On the other hand, environmental factors, such as nutritional status, could influence the disease's prognosis; several nutrients have immunomodulators, antioxidants, and anti-cardiometabolic risk properties which could reduce SLE severity and organ damage by decreasing the development of traditional and non-traditional CVD risk factors. Therefore, this critical literature review discusses the therapeutic potential of nutritional approaches that could modulate the development of the main comorbidities related to CVD risk in SLE patients.

Selenofolate inhibits the proliferation of IGROV1 cancer cells independently from folate receptor alpha

Cancer is one of the main causes of human mortality worldwide and novel chemotherapeutics are required due to the limitations of conventional cancer therapies. For example, using redox selenium compounds as novel chemotherapeutics seem to be very promising. The objective of this study was to explore if folate could be used as a carrier to deliver a newly synthesised selenium derivative selenofolate into cancer cells. Particularly, the cytotoxic effects of this selenofolate compound were investigated in a variety of cancer cell types including lung, liver, and cervical cancers and specifically IGROV1 cells. Our results showed that selenofolate inhibits the growth of cancer cells in-vitro. However, despite the expectations, folate receptor alpha (FRα) was not involved in the transportation of selenofolate compound into the cells i.e. growth inhibition was independent of FRα, suggesting that multiple transporters (e.g. reduced folate carrier-1) are possibly involved in the delivery and internalisation of folate in IGROV1 cells. Additionally, selenofolate did not exert cell death through apoptosis. Instead, anti-proliferative activity showed to be the main cause of growth inhibition of selenolofate in the IGROV1 cell line. In conclusion, selenofolate inhibits the growth of cancer cells and thus, may be explored further as a potential chemotherapeutic agent.

Folinic acid over rescue of high dose methotrexate: How problematic citations conserve discredited concepts

BACKGROUND

The outdated axiom that the dose of Folinic acid (FA) rescue used after high dose Methotrexate (HDMTX) should be kept to a minimum in order to prevent a reduction of prognosis ("over rescue") continues to be expressed even though the concept has been seriously challenged. Study aim The ways "problematic citations" are used to support an old theory, such as this, was examined.

RESULTS

Ten patterns of "problematic citation" use were identified. In 8 of these patterns the articles used were scientifically sound and the problem was with the articles citing them. However in 2 other pattens, the articles and their conclusions were flawed and citing them, apparently, resulted from accepting the presented data or conclusions as sound and valid. The patterns were 1. Claims based on data that are not present in the cited article. 2. Selective inclusion of data from cited articles. 3. Citation of misleading data presented only in the abstract. 4. Reporting trends as statistically significant. 5. Copying the citations used by others without checking the article. 6. Acceptance of illusionary truth in spite of knowledge to the contrary. 7. Citation of reports not relevant to the population under discussion 8. Presenting opinions as facts without any citation. 9. Selective presentation of data sets that support the thesis while ignoring the data sets that show the opposite results. 10. Use of a title expressing what the authors intended to show but not what was found.

IMPLICATIONS

The containing acceptance of this old insupportable conjecture, in part, because of "problematic citations" has resulted in unnecessary neurocognitive damage to patients and may have resulted in the misconception that it is the outcome of HDMTX that may have lead to its abandonment in favour of more toxic therapies. Realisation that this is a significant problem in data analysis should lead authors and reviewers to be even more carefully in checking all references. The importance of high-quality reviews is clearly evident. The effect of "Canonization of false facts" is a serious impairment to the acceptance of new hypotheses that better express reality and could lead to improved treatment results. Authors are advised only to cite articles they have read in entirety not relying on the title, abstract or previous use and to check the content of citations before submission.

Corneal Epithelial Toxicity after Intravitreal Methotrexate Injection for Vitreoretinal Lymphoma: Clinical and In Vitro Studies

Methotrexate is widely used as an intraocular chemotherapy for vitreoretinal lymphoma (VRL). Although corneal toxicity has been reported in patients after intravitreal methotrexate injections, the incidence, outcome, and mechanism of the toxicity are unclear. Herein, we performed a clinical study to evaluate the incidence, predisposing factors, and treatment outcome of corneal epitheliopathy associated with intravitreal methotrexate injection. In addition, we directly investigated cytotoxic effects and mechanisms of methotrexate in cultures of human corneal epithelial cells (CECs). Medical chart reviews revealed that corneal epitheliopathy occurred in 15 eyes (22.7%, 12 patients) out of 66 eyes (45 patients) after intravitreal methotrexate injections for treatment of VRL. The use of topical anti-glaucoma medication was significantly associated with development of corneal epitheliopathy. The epitheliopathy resolved in all patients 2.4 months after onset. In culture, methotrexate decreased the survival of CECs by inducing apoptosis, increasing oxidative stress, suppressing proliferation, and upregulating inflammatory cytokines. The addition of folinic acid significantly protected the cells from the methotrexate-induced toxicity. Hence, our results suggest that care should be taken to minimize the contact of methotrexate with corneal epithelium during injection, and folic or folinic acid supplementation might be beneficial for preventing corneal complications in patients undergoing intravitreal methotrexate injections.