The dichotomous role of TGF-β in controlling liver cancer cell survival and proliferation

Hepatocellular carcinoma(HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and proliferative signals, which are determined by the balance between oncogenes and tumor suppressors.Transforming growth factor beta(TGF-β) is an effective growth inhibitor of epithelial cells including hepatocytes, through induction of cell cycle arrest, apoptosis, cellular senescence, or autophagy. The antitumorigenic effects of TGF-β are bypassed during liver tumorigenesis via multiple mechanisms.Furthermore, along with malignant progression, TGF-β switches to promote cancer cell survival and proliferation. This dichotomous nature of TGF-β is one of the barriers to therapeutic targeting in liver cancer. Thereafter, understanding the underlying molecular mechanisms is a prerequisite for discovering novel antitumor drugs that may specifically disable the growth-promoting branch of TGF-β signaling or restore its tumor-suppressive arm. This review summarizes how TGF-β inhibits or promotes liver cancer cell survival and proliferation, highlighting the functional switch mechanisms during the process.

Mineral nutrient imbalance,DNA lesion and DNA-protein crosslink involved in growth retardation of Vicia faba L.seedlings exposed to lanthanum ions

Effects of mineral nutrient imbalance,DNA lesion and DNA-protein crosslink on growth of Vicia faba L.seedlings hydroponically cultivated in concentrations of extraneous lanthanum（La） for 20 days were investigated in the present experiment.The results showed that contents of La,Cu or K elements in roots generally changed synchronously with those in leaves,while Ca,Fe,Zn,Mg,Mn or P in the roots altered inversely to those in the leaves.Thus,the extraneous La led to redistribution and imbalance of mineral nutrient elements in the roots and leaves.DNA lesion and DNA-protein crosslink were investigated by single cell gel electrophoresis（SCGE） and sodium dodecyl sulfate/potassium（SDS/K＋） precipitation methods,respectively.The results demonstrated that the increasing La induced DNA break and DNA-protein crosslinks（DPCs） in the seedlings.These results suggested that mineral nutrient imbalance,DNA lesion and DNA-protein crosslink were involved in the growth retardation and growth alteration of the seedlings,which may help to understand the mechanisms of rare earth elements（REEs） on plant growth.