Phenotypic switching of VEGF and collagen XVIII during hypoxia in head and neck squamous carcinoma cells

HSP47 in human diseases: Navigating pathophysiology, diagnosis and therapy

Heat shock protein 47 (HSP47) is a chaperone protein responsible for regulating collagen maturation and transport, directly impacting collagen synthesis levels. Aberrant HSP47 expression or malfunction has been associated with collagen-related disorders, most notably fibrosis. Recent reports have uncovered new functions of HSP47 in various cellular processes. Hsp47 dysregulation in these alternative roles has been linked to various diseases, such as cancer, autoimmune and neurodegenerative disorders, thereby highlighting its potential as both a diagnostic biomarker and a therapeutic target. In this review, we discuss the pathophysiological roles of HSP47 in human diseases, its potential as a diagnostic tool, clinical screening techniques and its role as a target for therapeutic interventions.

Targeting HSP47 and HSP70: promising therapeutic approaches in liver fibrosis management

Liver fibrosis is a liver disease in which there is an excessive buildup of extracellular matrix proteins, including collagen. By regulating cytokine production and the inflammatory response, heat shock proteins (HSPs) contribute significantly to a wider spectrum of fibrotic illnesses, such as lung, liver, and idiopathic pulmonary fibrosis by aiding in the folding and assembly of freshly synthesized proteins, HSPs serve as chaperones. HSP70 is one of the key HSPs in avoiding protein aggregation which induces its action by sending unfolded and/or misfolded proteins to the ubiquitin–proteasome degradation pathway and antagonizing influence on epithelial-mesenchymal transition. HSP47, on the other hand, is crucial for boosting collagen synthesis, and deposition, and fostering the emergence of fibrotic disorders. The current review aims to provide light on how HSP70 and HSP47 affect hepatic fibrogenesis. Additionally, our review looks into new therapeutic approaches that target HSP70 and HSP47 and could potentially be used as drug candidates to treat liver fibrosis, especially in cases of comorbidities.

Fluctuating roles of matrix metalloproteinase-9 in oral squamous cell carcinoma

One hallmark of cancer is the degradation of the extracellular matrix (ECM), which is caused by proteinases. In oral cancers, matrix metalloproteinases (MMPs), especially MMP-9, are associated with this degradation. MMPs break down the ECM allowing cancer to spread; they also release various factors from their cryptic sites, including cytokines. These factors modulate cell behavior and enhance cancer progression by regulating angiogenesis, migration, proliferation, and invasion. The development of early metastases is typical for oral cancer, and increased MMP-9 expression is associated with a poor disease prognosis. However, many studies fail to relate MMP-9 expression with metastasis formation. Contrary to earlier models, recent studies show that MMP-9 plays a protective role in oral cancers. Therefore, the role of MMP-9 is complicated and may fluctuate throughout the different types and stages of oral cancers.

The phosphoinositide 3-kinase signalling pathway as a therapeutic target in squamous cell carcinoma of the head and neck

Squamous cell carcinoma of the head and neck (SCCHN) is associated with high morbidity and mortality. Despite significant surgical advances and refinement in the delivery of chemotherapy and radiotherapy, prognosis has improved little in recent decades. Better local control has led to the late presentation of distant metastases and novel therapeutic agents are urgently required to prevent relapse, control disseminated disease and thus improve survival. PIK3CA encodes the p110alpha isoform of phosphoinositide 3-kinase (PI3-K) and is important in SCCHN, aberrations in its activity occurring early in the oncogenic process. PI3-K signalling promotes cell survival, proliferation, invasion and angiogenesis, all contributing to tumour progression. Activation of the PI3-K pathway may also mediate resistance to chemotherapy, radiotherapy and novel therapeutic agents such as epidermal growth factor receptor inhibitors. Elements of this signalling matrix, therefore, offer attractive therapeutic targets in SCCHN as inhibition of many malignant characteristics, as well as sensitisation to multiple treatment modalities, could be anticipated.

Mechanisms for the magnolol-induced cell death of CGTH W-2 thyroid carcinoma cells

Magnolol, a substance purified from the bark of Magnolia officialis, inhibits cell proliferation and induces apoptosis in a variety of cancer cells. The aim of this study was to study the effects of magnolol on CGTH W-2 thyroid carcinoma cells. After 24 h treatment with 80 microM magnolol in serum-containing medium, about 50% of the cells exhibited apoptotic features and 20% necrotic features. Cytochrome-c staining was diffused in the cytoplasm of the apoptotic cells, but restricted to the mitochondria in control cells. Western blot analyses showed an increase in levels of activated caspases (caspase-3 and -7) and of cleaved poly (ADP-ribose) polymerase (PARP) by magnolol. Concomitantly, immunostaining for apoptosis inducing factor (AIF) showed a time-dependent translocation from the mitochondria to the nucleus. Inhibition of either PARP or caspase activity blocked magnolol-induced apoptosis, supporting the involvement of the caspases and PARP. In addition, magnolol activated phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and inactivated Akt by decreasing levels of phosphorylated PTEN and phosphorylated Akt. These data suggest that magnolol promoted apoptosis probably by alleviating the inhibitory effect of Akt on caspase 9. Furthermore, inhibition of PARP activity, but not of caspase activity, completely prevented magnolol-induced necrosis, suggesting the notion that it might be caused by depletion of intracellular ATP levels due to PARP activation. These results show that magnolol initiates apoptosis via the cytochrome-c/caspase 3/PARP/AIF and PTEN/Akt/caspase 9/PARP pathways and necrosis via PARP activation.

Endostatin inhibits nitric oxide and diminishes VEGF and collagen XVIII in squamous carcinoma cells

Low pO(2) values are a common finding among oral squamous cell carcinomas (SCC). Our objective was to determine the role that oxygen tension plays on the direct tumor effect of endostatin (ES). Squamous carcinoma cell lines were grown under normoxic or hypoxic conditions and treated with endostatin (ES), nitric oxide (NO) donors, NO scavengers, NO synthase inhibitors, or transduced with AdenoVec-hEndo or AdenoVec Null vectors. The expression of vascular endothelial growth factor (VEGF) and collagen XVIII were determined by RT-PCR and protein levels assessed by Western blot analyses. Our studies demonstrated that collagen XVIII and VEGF are expressed and responsive to ES in a limited number of SCC cell lines during normoxia but were most responsive when grown under hypoxic conditions. VEGF and collagen XVIII were downregulated by both ES and transduction of cells with AdenoVec-hEndo. The effects of ES on SCC cells were enhanced by aminoguanidine (Ag), L-NAME, and diphenyleneiodonium chloride (DPI). Endostatin and transduced with ES vectors diminished the levels of NO whereas NO donors enhanced VEGF expression and collagen XVIII expression. In conclusion, the direct effect of endostatins on tumor cells is most effective under conditions of low oxygen tension and can be potentiated by the use of nitric oxide synthase inhibitors or NO scavengers.