salvianolic-acid-B and Mouth-Neoplasms

Our previous study demonstrated a progressive glycolytic perturbation during the course of DMBA-induced hamster oral carcinogenesis, which was attenuated by salvianolic acid B (Sal-B) treatment along with decreased incidences of oral squamous cell carcinoma (OSCC) formation. It was proposed that metabolic modulation should be an additional mode of action attributable to Sal-B's anti-carcinogenic activity. However, the molecular mechanisms underlying Sal-B-induced metabolic modulation function remained elusive. In the present study, we performed next-generation sequencing (NGS) profiling in the same animal model and found Sal-B treatment evoked a general downregulation of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and hypoxia inducible factor 1α subunit (HIF-1α) signaling pathways, which might contribute to Sal-B's metabolic modulation activity. The inhibitory effects of Sal-B on aerobic glycolysis, as well as PI3K/AKT and HIF-1α signaling pathways, were validated in two well-characterized OSCC cell lines (Cal27 and HN4), and premalignant oral Leuk1 cells and Sal-B treatment led to elevation of the loss of mitochondrial membrane potential (MMP), increased cell apoptosis, and reduced abilities of colony formation. Rescue assays suggested that compared with Sal-B treatment group, Akt or hif-1a overexpression attenuated the inhibitory effect of Sal-B on glucose uptake and intracellular lactate level. Taken together, our results suggested that Sal-B modulated aberrant glucose metabolism via the PI3K/AKT/HIF-1α signaling pathways, which might contribute to the anti-carcinogenic activity of Sal-B.

Topics: Animals; Apoptosis; Benzofurans; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Clone Cells; Disease Models, Animal; Glucose; Glycolysis; Hypoxia-Inducible Factor 1, alpha Subunit; Lactates; Male; Membrane Potential, Mitochondrial; Mesocricetus; Models, Biological; Mouth Neoplasms; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction

Oral cancer typically develops from hyperplasia through dysplasia to carcinoma with a multistep process of carcinogenesis involving genetic alterations resulting in aberrant cellular appearance, deregulated cell growth, and carcinoma. The metabolic transformation during the process of oral carcinogenesis and its implications for cancer therapy have not been extensively investigated. Here, we report a metabonomic study on a classical model of 7,12-dimethylbenz(a)anthracene (DMBA)-induced oral carcinogenesis in hamsters to delineate characteristic metabolic transformation during the carcinogenesis using gas chromatography time-of-flight mass spectrometry (GC-TOF MS). Salvianolic acid B (Sal-B), isolated from Salvia miltiorrhiza Bge, and Breviscapine, a flavonoid isolated from Herba Erigerontis, were used to treat the hamsters exposed to DMBA to investigate the molecular mechanism of the inhibitory effect of the two agents on oral carcinogenesis. The dynamic changes of serum metabolic profiles indicated that both Sal-B and Breviscapine were able to attenuate DMBA-induced metabolic perturbation, which is consistent with the histopathological findings that Sal-B and Breviscapine significantly decreased the squamous cell carcinoma (SCC) incidence in the two treatment groups. Significant alterations of key metabolic pathways, including elevated glutaminolysis and glycolysis, and decreased cholesterol and myo-inositol metabolism, were observed in the DMBA-induced model group, which were attenuated or normalized by Sal-B or Breviscapine treatment. Elevated inflammation and tumor angiogenesis at gene and metabolite expression levels were also observed in DMBA-induced oral dysplasia and SCC but were attenuated or normalized by Sal-B and Breviscapine along with significantly decreased incidences of SCC formation.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Benzofurans; Carcinogens; Cricetinae; Drug Interactions; Flavonoids; Gas Chromatography-Mass Spectrometry; Histocytochemistry; Male; Mesocricetus; Metabolic Networks and Pathways; Metabolome; Metabolomics; Mouth Neoplasms; Neovascularization, Pathologic

Our previous studies showed that Salvianolic acid B (Sal B) inhibited 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters and such anti-cancer effects might be related to the inhibition of angiogenesis. This study was aimed to further investigate the anti-proliferative effect of Sal B on the most common type of oral cancer, oral squamous cell carcinoma (OSCC) and the possible mechanisms of action with respect to angiogenesis inhibition.. Two well-characterized oral squamous cell carcinoma cell lines, CAL27 and SCC4, and premalignant leukoplakia cells were treated with different concentrations of Sal B. Cytotoxicity was assessed by MTT assay. cDNA microarray was utilized to evaluate the expression of 96 genes known to be involved in modulating the biological processes of angiogenesis. Real-time reverse transcription-polymerase chain reaction analysis was conducted to confirm the cDNA microarray data.. Sal B induced growth inhibition in OSCC cell lines but had limited effects on premalignant cells. A total of 17 genes showed a greater than 3-fold change when comparing Sal B treated OSCC cells to the control. Among these genes, HIF-1α, TNFα and MMP9 are specifically inhibited, expression of THBS2 was up-regulated.. Sal B has inhibitory effect on OSCC cell growth. The antitumor effect can be attributed to anti-angiogenic potential induced by a decreased expression of some key regulator genes of angiogenesis. Sal B may be a promising modality for treating oral squamous cell carcinoma.

Topics: Angiogenesis Inhibitors; Antineoplastic Agents, Phytogenic; Benzofurans; Carcinoma, Squamous Cell; Cell Line; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Drugs, Chinese Herbal; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Leukoplakia; Matrix Metalloproteinase 9; Mouth Neoplasms; Oligonucleotide Array Sequence Analysis; Phytotherapy; Reverse Transcriptase Polymerase Chain Reaction; Salvia miltiorrhiza; Thrombospondins; Tumor Necrosis Factor-alpha; Up-Regulation

Salvia miltiorrhiza (SM) has been used clinically in Asian countries to improve the microcirculation in the human body. Salvianolic acid B (Sal B), a pure compound extracted from SM, has been reported to be effective against fibrosis and ischemia-reperfusion injury, possibly through its anti-lipid peroxidation action. But the effect of Sal B on oral premalignant lesion and oral carcinogenesis remains unexplored. It is our interest to investigate the chemopreventive effect of Sal B on 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters with respect to angiogenesis. Seventy male Syrian golden hamsters were randomly divided into five groups, with two of 20 and three of 10. DMBA solution (0.5% in acetone) was applied topically to the left cheek pouch of male Syrian golden hamsters in Groups A and B, while animals in Group C were painted with acetone, three times a week for 6 weeks. For the next 18 weeks, animals in Groups B and D received Sal B daily (10 mg/kg body wt/day) by gavage, animals in Groups A and C received same volume of saline. Animals in Group E received no treatment and served as blank control. At the end of the experiment, animals were killed and tissue samples were collected for histopathological and immunohistochemical examinations. The results showed that Sal B significantly decreased the squamous cell carcinoma (SCC) incidence from 64.7 (11/17) to 16.7% (3/18) (P=0.004); angiogenesis was inhibited in dysplasia and SCC (P<0.01), with a simultaneous decrease in the immunostaining of hypoxia-inducible factor 1alpha and vascular endothelium growth factor protein (P<0.05). The results suggested that Sal B had inhibitory effect against the malignant transformation of oral precancerous lesion and such inhibition may be related to the inhibition of angiogenesis.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Administration, Oral; Animals; Benzofurans; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Chemoprevention; Cricetinae; Male; Mesocricetus; Mouth Neoplasms; Neovascularization, Pathologic; Precancerous Conditions; Random Allocation