ABSTRACT
Mitochondrial respiratory defects have been implicated in cancer progression and metastasis, but how they control tumor cell aggressiveness remains unclear. Here, we demonstrate that a mitochondrial respiratory defect induces nuclear factor-erythroid 2 like 1 (NFE2L1) expression at the transcriptional level via reactive oxygen species (ROS)-mediated STAT3 activation. We identified syntaxin 12 (STX12) as an effective downstream target of NFE2L1 by performing cDNA microarray analysis after the overexpression and depletion of NFE2L1 in hepatoma cells. Bioinformatics analysis of The Cancer Genome Atlas Liver Hepatocellular carcinoma (TCGA-LIHC) open database (n = 371) also revealed a significant positive association (r = 0.3, p = 2.49 × 10-9) between NFE2L1 and STX12 expression. We further demonstrated that STX12 is upregulated through the ROS/STAT3/NFE2L1 axis and is a key downstream effector of NFE2L1 in modulating hepatoma cell invasiveness. In addition, gene enrichment analysis of TCGA-LIHC also showed that epithelial-mesenchymal transition (EMT)-related core genes are significantly upregulated in tumors co-expressing NFE2L1 and STX12. The positive association between NFE2L1 and STX12 expression was validated by immunohistochemistry of the hepatocellular carcinoma tissue array. Finally, higher EMT gene enrichment and worse overall survival (p = 0.043) were observed in the NFE2L1 and STX12 co-expression group with mitochondrial defect, as indicated by low NDUFA9 expression. Collectively, our results indicate that NFE2L1 is a key mitochondrial retrograde signaling-mediated primary gene product enhancing hepatoma cell invasiveness via STX12 expression and promoting liver cancer progression.
ABSTRACT
Plants have evolved a vast chemical cornucopia to support their sessile lifestyles. Man has exploited this natural resource since Neolithic times and currently plant-derived chemicals are exploited for a myriad of applications. However, plant sources of most high-value natural products (NPs) are not domesticated and therefore their production cannot be undertaken on an agricultural scale. Further, these plant species are often slow growing, their populations limiting, the concentration of the target molecule highly variable and routinely present at extremely low concentrations. Plant cell and organ culture constitutes a sustainable, controllable and environmentally friendly tool for the industrial production of plant NPs. Further, advances in cell line selection, biotransformation, product secretion, cell permeabilisation, extraction and scale-up, among others, are driving increases in plant NP yields. However, there remain significant obstacles to the commercial synthesis of high-value chemicals from these sources. The relatively recent isolation, culturing and characterisation of cambial meristematic cells (CMCs), provides an emerging platform to circumvent many of these potential difficulties. [BMB Reports 2016; 49(3): 149-158].
Subject(s)
Biological Products/metabolism , Cell Culture Techniques/methods , Plant Cells/metabolism , Biotransformation , Cells, Immobilized/metabolism , Plant Roots/cytologyABSTRACT
Humans have utilised plant derived natural products as medicines for millenia. Moreover, many contemporary pharmaceuticals are also natural products or derivatives thereof. However, the full potential of these compounds remains to be exploited because often they are: complex and difficult to synthesise; found in low quantities; produced by undomesticated and sometimes rare plants; and, their synthesis is routinely influenced by weather conditions. Potentially, the in vitro culture of cells from the corresponding plant species could circumvent some of these problems but the growth of plant cells on an industrial scale is also problematic. The recent isolation and culture of cambial meristematic cells (CMCs), stem cells which ordinarily generate the plant vasculature, may now provide a key platform technology to help realise the full potential of plant natural products.
Subject(s)
Biological Products/chemistry , Biological Products/metabolism , Cambium/cytology , Cambium/metabolism , Biological Products/history , Biotechnology/methods , Cambium/chemistry , Cell Culture Techniques , Cell Dedifferentiation , Cell Proliferation , Cells, Cultured , Diterpenes/isolation & purification , History, 17th Century , History, 18th Century , History, 19th Century , History, Ancient , History, Medieval , Humans , Paclitaxel/biosynthesis , Plant Cells/chemistry , Plant Cells/metabolism , Plants, Medicinal/chemistry , Plants, Medicinal/metabolism , Taxus/chemistry , Taxus/cytologyABSTRACT
We encapsulated recombinant human epidermal growth factor (rhEGF) into nano-liposomes (NLs) system for topical delivery. The rhEGF-loaded NLs were prepared using a high pressure homogenization method. Morphology and overall particle distribution of NLs were investigated using transmission electron microscopy (TEM) and high resolution microscope (CytoViva™). Particle size, zeta (ζ) potential and encapsulation efficiency were measured and the percutaneous delivery of NLs was evaluated using Franz diffusion cells and immunofluorescence confocal laser scanning microscopy (CLSM). The mean particle size, zeta potential and encapsulation efficiency of the NLs were 155.57 ± 2.59 nm, -57.92 ± 4.35 mV and 9.00 ± 0.39%, respectively. TEM and microscopic analysis showed spherical, very even-sized vesicles approximately 150 nm. The skin permeation and localization of rhEGF were enhanced by NLs. CLSM image analysis provided that the NLs enhanced the permeation and localization of rhEGF in rat skin by facilitating entry through pores of skin.
