[Regulation of tumor cell glycometabolism and tumor therapy]

Tumor cells have unique energy metabolism phenomena, namely high glucose absorption, aerobic glycolysis and high lactic acid production, which are characterized by down-regulation of related proteins involved in oxidative metabolism in tumor cells, and up-regulation of glucose transporters and monocarboxylate transporters. Studies have shown that drugs that target tumor cell glucose metabolism have the ability to selectively kill tumor cells, bringing new hope for tumor treatment. Tumor stem cells are considered to be the root cause of tumor recurrence, metastasis and poor prognosis, and their energy metabolism characteristics have not yet been agreed. Studies have shown that reversing the energy metabolism of tumor stem cells can increase their chemosensitivity. This article reviews recent studies on tumor and tumor stem cell glucose metabolism and the opportunities and challenges of tumor treatment through targeting glucose metabolism, which might provide new ideas and opportunities for clinical tumor therapy.

T-lymphocyte and glycemic status after vitamin D treatment in type 1 diabetes: A randomized controlled trial with sequential crossover

BACKGROUND

Type 1 diabetes mellitus (T1D) is mediated by autoaggressive T effector cells with an underlying regulatory T-cell (Treg) defect. Vitamin D deficiency is highly prevalent in T1D, which can aggravate immune dysfunction. High-dose vitamin D treatment may enhance Tregs and improve metabolism in T1D patients.

METHODS

In a randomized double-blind placebo-controlled trial with crossover design, patients received either for 3 months cholecalciferol 4000 IU/d followed by 3 months placebo or the sequential alternative. Thirty-nine T1D patients (19 women and 20 men) completed the trial.

RESULTS

Primary outcome was a change of Tregs, secondary HbA1C, and insulin demand. Effects were evaluated based on intra-individual changes between treatment and placebo periods for outcome measures. Exploratory analyses included vitamin D system variant genotyping and C-peptide measurements. Median 25(OH)D₃ increased to 38.8 ng/ml with males showing a significantly stronger increase (p = .003). T-lymphocyte profiles did not change significantly (p > 2); however, the intra-individual change of Tregs between males and females was different with a significantly stronger increase in men (p = .017), as well as between genotypes of the vitamin D receptor (Apa, Taq, and Bsm: genotypes aa, TT, and bb; p = .004-0.015). Insulin demands declined significantly (p = .003-.039) and HbA1C improved (p < .001). Random C-peptide levels were low but rising (median, 0.125 ng/ml; range, 0.02-0.3) in 6 patients. No toxicity was observed.

CONCLUSION

A daily vitamin D dose of 4000 IU for 3 months was well tolerated and enhanced Tregs in males. Glucometabolic control improved in all. Subsequent larger trials need to address ß-cell function and genotyping for individualized vitamin D doses.