Isocudraxanthone K induces growth inhibition and apoptosis in oral cancer cells via hypoxia inducible factor-1α

Identification of Novel Parishin Compounds from the Twig of Maclura tricuspidata and Comparative Analysis of Parishin Derivatives in Different Parts

Parishin compounds are rare polyphenolic glucosides mainly found in the rhizome of the traditional Chinese medicinal plant, Gastrodia elata. These constituents are reported to have several biological and pharmacological activities. In the present study, two novel parishin derivatives not previously reported as plant-based phytochemicals were identified from a twig of Maclura tricuspidata (MT) and two new compounds were elucidated as 1-(4-(β-d-glucopyranosyloxy)benzyl)-3-hydroxy-3-methylpentane-1,5-dioate (named macluraparishin E) and 1,3-bis(4-(β-d-glucopyranosyloxy)benzyl)-3-hydroxy-3-methylpentane- 1,5-dioate (macluraparishin C), based on the experimental data obtained by UV-Visible (UV-Vis) spectroscopy, high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) and nuclear magnetic resonance (NMR) spectroscopy. Additionally, gastrodin, parishin A and parishin B were positively identified by spectroscopic evidence and the comparison of HPLC retention time with the corresponding authentic standards. Gastrodin, parishin A and parishin B, macluraparishin E and macluraparishin C were found to be the most abundant constituents in the MT twig. The compositions and contents of these constituents were found to vary depending on the different parts of the MT plant. In particular, the contents of parishin A, parishin B, macluraparishin C and macluraparishin E were higher in the twig, bark and root than in the leaves, xylem and fruit.

Cudraxanthone L inhibits gastric cancer by regulating the MAPK signalling and promoting FAS-mediated pathway

Gastric cancer (GC) is one of the most common malignancies and has the second highest lethal rate in the world; thus, finding new medicines with high potency and low toxicity is urgent. Cudrania tricuspidata (Carr.) Bur. ex Lavallee (Moraceae) is a traditional medicinal herb that is considered to have antitumour efficacy. We extracted and isolated cudraxanthone L (CXL) from Cudrania tricuspidata and evaluated its anti-cancer efficacy. CXL treatment inhibited angiogenesis of chorioallantoic membrane (CAM) and repressed the cell viability of various human cancer cells, indicating it presented the antitumour potential. Among them, CXL presented the best inhibitory effects on MGC803 cells. In addition, the invasion, migration and clonogenicity were significantly repressed, S phase of the cell cycle was arrested, and apoptosis was induced when MGC803 cells were treated with CXL. The results of RNA sequencing, qRT-PCR and western blotting verified that CXL regulated the MAPK signalling pathway and induced apoptosis by FAS-mediated pathway. The in vivo data revealed that CXL arrested tumour growth without toxic effects and upregulated the protein levels in FAS-mediated pathway in MGC803 gastric cancer-bearing mice. In summary, we demonstrate CXL presents impactful anti-GC efficacy by regulating the MAPK signalling pathway and promoting the FAS-mediated pathway.

Chemopreventive and Anti-tumor Potential of Natural Products in Oral Cancer

Oral cancer (OC) is a multifactorial disease caused by isolated or combined risk factors related to tobacco, alcohol consumption, and human papillomavirus infection. It is an aggressive pathology with a low five-year survival rate after surgery, chemotherapy, and/or radiotherapy, frequently associated with severe side effects. Drugs with the highest anti-tumor effect are obtained from natural products with diverse biological and molecular activities and potential chemopreventive and anticancer properties. This review summarizes the natural products reported to have the chemopreventive and anti-tumor potential for OC treatment, showing that several of these compounds are promising candidates as chemopreventive agents, and those with the highest anti-tumor potential induce apoptosis and inhibit proliferation and metastasis-related processes. For this reason, natural products have the potential to be important preventive and therapeutic options for OC in the future.

Intersecting Mechanisms of Hypoxia and Prostaglandin E2-Mediated Inflammation in the Comparative Biology of Oral Squamous Cell Carcinoma

The importance of inflammation in the pathogenesis of cancer was first proposed by Rudolph Virchow over 150 years ago, and our understanding of its significance has grown over decades of biomedical research. The arachidonic acid pathway of inflammation, including cyclooxygenase (COX) enzymes, PGE2 synthase enzymes, prostaglandin E2 (PGE2) and PGE2 receptors has been extensively studied and has been associated with different diseases and different types of cancers, including oral squamous cell carcinoma (OSCC). In addition to inflammation in the tumour microenvironment, low oxygen levels (hypoxia) within tumours have also been shown to contribute to tumour progression. Understandably, most of our OSCC knowledge comes from study of this aggressive cancer in human patients and in experimental rodent models. However, domestic animals develop OSCC spontaneously and this is an important, and difficult to treat, form of cancer in veterinary medicine. The primary goal of this review article is to explore the available evidence regarding interaction between hypoxia and the arachidonic acid pathway of inflammation during malignant behaviour of OSCC. Overlapping mechanisms in hypoxia and inflammation can contribute to tumour growth, angiogenesis, and, importantly, resistance to therapy. The benefits and controversies of anti-inflammatory and anti-angiogenic therapies for human and animal OSCC patients will be discussed, including conventional pharmaceutical agents as well as natural products.

Final-2 targeted glycolysis mediated apoptosis and autophagy in human lung adenocarcinoma cells but failed to inhibit xenograft in nude mice

Natural products derived from fruits have multiple antitumor potential. However, very few have been developed for clinical therapy, due to the limited efficiency or insufficient study of their mechanism. Since lung cancer is the most common cancer in the world, there is still need to explore novel compounds but their molecular mechanisms remain elusive. In this study, a new compound Final-2 was synthesized. Final-2 exhibited antitumor activity in A549 cells by promoting apoptosis and blocking autophagy. Moreover, Final-2 significantly induced G₀/G₁ cycle arrest and inhibited cell malignancy. Intracellular molecular targets investigation showed that Final-2 inhibited the Gluts, which resulted in downregulation of glucose metabolism and the oncogene c-Myc and Kras expression in vitro. However, according the autophagy inhibitor CQ and Kras inhibitors test, low concentration of Final-2 showed some controversial effects. In A549 xenograft mice model, 10 mg/kg and 20 mg/kg of Final-2 showed no and partial tumor inhibition, respectively. Moreover, a high dose of Final-2 induced serious liver necrosis. Therefore, the results indicated that even though Final-2 was efficient in suppressing the cancer cell growth in vitro, it failed to inhibit tumors in vivo and showed significant liver toxicity, which was its limitation as a potential antitumor drug.

Bioactive compounds from Cudrania tricuspidata: A natural anticancer source

The tumor is becoming a critical threat to our lives in these years. Searching for antitumor substances from natural products is a great interest of scientists. Cudrania tricuspidata (C. tricuspidata) is a regional plant containing 158 flavonoids and 99 xanthones, and others ingredients with favorable bioactivity. This review comprehensively analyzes the antitumor compounds from C. tricuspidata against different tumors, and 78 flavonoids plus xanthones are considered as underlying antineoplastic. Importantly, the structure of preylation groups is the primary source of antitumor activity among 45 flavonoids plus xanthones, which could be a direction of structural modification for a better antitumor ability. Additionally, the fruits are also preferable sources of antitumor compounds compared to the roots and barks due to the abundant isoflavones and sustainability. However, many studies only focused on the cells viability inhibition of the compounds, the underlying molecular mechanisms, and the intracellular targets remain ambiguous. In conclusion, C. tricuspidata has a great potential for anti-tumor prevention or therapy, but more attention should be paid to deeper research in vitro and in vivo models.

Down-regulation of BAG3 inhibits proliferation and promotes apoptosis of glioblastoma multiforme through BAG3/HSP70/HIF-1α signaling pathway

Bcl2-associated athanogene 3 (BAG3) belongs to the BAG family and regulates many biologic behaviors of tumors. When tumor cells are in a hypoxic condition, BAG3 protein expression level increases, as does HIF-1α which is an important transcription factor induced by hypoxia. Glioblastoma is one of the typical solid tumors existing in a hypoxic microenvironment that can activate expression of BAG3 and HIF-1α. This research aimed to reveal the relationship between BAG3 and HIF-1α and their effects in glioblastoma multiforme. We found that down-regulated BAG3 inhibited proliferation and promoted apoptosis of glioblastoma multiforme U87 and U251 cell lines by decreasing HIF-1α expression level. The mechanism of BAG3 regulating HIF-1α is mainly through increasing degradation of HIF-1α by HSP70. When HIF-1α was up-regulated, induced by HIF-1α plasmid transfection on the basis of down-regulation of BAG3, the proliferation inhibition and apoptosis promotion were partially reversed. This novel result showed, for the first time, that down-regulation of BAG3 resulted in a low expression of HIF-1α under both normoxic or hypoxic conditions and finally caused inhibited proliferation and promoted apoptosis in glioblastoma. The mechanism of down-regulated BAG3 decreased HIF-1α protein expression through enhancing formation of HSP70-HIF-1α complex and promoting degradation of HIF-1α by HSP70.

Hypoxia induced EMT: A review on the mechanism of tumor progression and metastasis in OSCC

Hypoxia, a condition of low oxygen tension in tissues, has emerged as a crucial factor in tumor pathophysiology. Hypoxic microenvironment gives rise to altered cellular metabolism and triggers varied molecular responses. These responses promote tumor progression and confer radiation resistance and chemo resistance to tumors. The predominant molecules that are associated with hypoxia research are the hypoxia inducible factors (HIFs). HIFs are known to regulate a large group of genes that are involved in cell survival, proliferation, motility, metabolism, pH regulation, extracellular matrix function, inflammatory cell recruitment and angiogenesis by inducing the expression of their downstream target genes. The process of epithelial to mesenchymal transition (EMT) has been associated with metastasis in cancer. Reports also suggest that hypoxia triggers EMT in several types of cancer including breast cancer, prostate cancer and oral cancer. Oral cancer is a predominant cancer in Central and South East Asia. However, in the recent times, the incidence rates of oral cancer have been increasing in Northern and Eastern Europe as well. This review articulates the role of hypoxia and the associated factors like HIFs in inducing EMT in oral cancer (OSCC).

Anticancer Natural Compounds as Epigenetic Modulators of Gene Expression

Accumulating evidence shows that hallmarks of cancer include: "genetic and epigenetic alterations leading to inactivation of cancer suppressors, overexpression of oncogenes, deregulation of intracellular signaling cascades, alterations of cancer cell metabolism, failure to undergo cancer cell death, induction of epithelial to mesenchymal transition, invasiveness, metastasis, deregulation of immune response and changes in cancer microenvironment, which underpin cancer development". Natural compounds as bioactive ingredients isolated from natural sources (plants, fungi, marine life forms) have revolutionized the field of anticancer therapeutics and rapid developments in preclinical studies are encouraging. Natural compounds could affect the epigenetic molecular mechanisms that modulate gene expression, as well as DNA damage and repair mechanisms. The current review will describe the latest achievements in using naturally produced compounds targeting epigenetic regulators and modulators of gene transcription in vitro and in vivo to generate novel anticancer therapeutics.

Functional significance of CD105-positive cells in papillary renal cell carcinoma

Background

CD105 was postulated as a renal cell carcinoma (RCC) stem cell marker, and CD133 as a putative RCC progenitor. Hypoxia, a natural microenvironment that prevails in tumors, was also incorporated into the study, especially in terms of the promotion of hypothetical stem-like cell properties.

Methods

Within this study, we verify the existence of CD105+ and CD133+ populations in selected papillary subtype RCC (pRCC) cell lines. Both populations were analyzed for correlation with stem-like cell properties, such as stemness gene expression, and sphere and colony formation. For the preliminary analysis, several RCC cell lines were chosen (786-O, SMKT-R2, Caki-2, 796-P, ACHN, RCC6) and the control was human kidney cancer stem cells (HKCSC) and renal cells of embryonic origin (ASE-5063). Four cell lines were chosen for further investigation: Caki-2 (one of the highest numbers of CD105+ cells; primary origin), ACHN (a low number of CD105+ cells; metastatic origin), HKCSC (putative positive control), and ASE-5063 (additional control).

Results

In 769-P and RCC6, we could not detect a CD105+ population. Hypoxia variously affects pRCC cell growth, and mainly diminishes the stem-like properties of cells. Furthermore, we could not observe the correlation of CD105 and/or CD133 expression with the enhancement of stem-like properties.

Conclusions

Based on this analysis, CD105/CD133 cannot be validated as cancer stem cell markers of pRCC cell lines.

Cudrania tricuspidata: an updated review on ethnomedicine, phytochemistry and pharmacology

This review summarized the botany, traditional uses, phytochemistry and pharmacology ofCudrania tricuspidata, and the limitations of the studies on this species were also discussed so as to serve as the basis for further research and development of this medicinal plant.