Folic acid depletion as well as oversupplementation helps in the progression of hepatocarcinogenesis in HepG2 cells

Abstract

Folate ingestion below and above the physiologic dose has been shown to play a tumorigenic role in certain cancers. Also, excessive folate supplementation after establishment of pre-established lesions led to an advancement in the growth of a few tumors. However, such information has not yet been achieved in the case of HCC. In our study, HepG2 cells were administered with three different concentrations of folic acid i.e. folic acid normal (FN) (2.27 µM), folic acid deficient (FD) (no folic acid), folic acid oversupplementation (FO) (100 µM) for 10 days. Intracellular folate levels were assayed by Elecsys Folate III kit based method. The migratory and invasive abilities were estimated by transwell migration and matrigel invasion methods respectively. FACS was done to evaluate cell viability and apoptosis. Agarose-coated plates were used to access cancer stem cells (CSCs) number. Quantitative RT-PCR and western blotting approaches were used for gene and protein expression of certain tumor suppressor genes (TSGs), respectively. FD cells depicted increased migration, invasion, apoptosis, necrosis and decreased cell viability, CSCs. On the other hand, FO cells showed increased migration, invasion, cell viability and number of CSCs and decreased apoptosis and necrosis. TSGs revealed diminished expression with both FA modulations with respect to FN cells. Thus, FA deficiency as well as abundance enhanced the HCC progression by adapting different mechanisms.

The Hidden Dangers of Excess Folate, Uncovering the Molecular Mechanisms

“…In cell culture studies, FA depletion and supplementation enhanced the transformation of keratinocytes infected by the human papilloma virus [162,163]. Furthermore, depletion and over-supplementation of FA led to increased progression, migration, and invasion of the hepatocarcinoma HepG2 cells [164]. Similarly, in human lymphoblastoid cell lines, excess FA mimicked folate restriction by similarly impacting the oxidative stress response, DNA damage repair, and DNA methylation [124].…”

The relationship between folic acid and nonalcoholic fatty liver disease

“…In contrast, cells treated with excess FA exhibited heightened migration, invasion, cellular activity, CSC numbers, and reduced apoptosis and necrosis. 120 The underlying mechanism may involve excessive FA depleting MTHFR, creating a "methyl trap" that interferes with normal DNA methylation regulation. Furthermore, FA supplementation can intensify the endoplasmic reticulum stress in tumour cells, enhancing their survival and metastatic potential.…”

“…Cells deficient in FA showed increased migration, invasion, apoptosis, necrosis and diminished CSC activity. In contrast, cells treated with excess FA exhibited heightened migration, invasion, cellular activity, CSC numbers, and reduced apoptosis and necrosis 120 . The underlying mechanism may involve excessive FA depleting MTHFR, creating a “methyl trap” that interferes with normal DNA methylation regulation.…”