MCF-7 cell - derived exosomes were involved in protecting source cells from the damage caused by tributyltin chloride via transport function.

Tributyltin chloride (TBTC) is a ubiquitous environmental pollutant with various adverse effects on human health. Exosomes are cell - derived signaling and substance transport vesicles. This investigation aimed to explore whether exosomes could impact the toxic effects caused by TBTC via their transport function. Cytotoxicity, DNA and chromosome damage caused by TBTC on MCF-7 cells were analyzed with CCK-8, flow cytometry, comet assay and micronucleus tests, respectively. Exosomal characterization and quantitative analysis were performed with ultracentrifugation, transmission electron microscope (TEM) and bicinchoninic acid (BCA) methods. TBTC content in exosomes was detected with Liquid Chromatography-Mass Spectrometry (LC-MS). The impacts of exosomal secretion on the toxic effects of TBTC were analyzed. Our data indicated that TBTC caused significant cytotoxicity, DNA and chromosome damage effects on MCF-7 cells, and a significantly increased exosomal secretion. Importantly, TBTC could be transported out of MCF-7 cells by exosomes. Further, when exosomal secretion was blocked with GW4869, the toxic effects of TBTC were significantly exacerbated. We concluded that TBTC promoted exosomal secretion, which in turn transported TBTC out of the source cells to alleviate its toxic effects. This investigation provided a novel insight into the role and mechanism of exosomal release under TBTC stress.

mTORC1 - TFEB pathway was involved in sodium arsenite induced lysosomal alteration, oxidative stress and genetic damage in BEAS-2B cells.

The mechanistic target of rapamycin (RAPA) complex 1 (mTORC1) - transcription factor EB (TFEB) pathway plays a crucial role in response to nutritional status, energy and environmental stress for maintaining cellular homeostasis. But there is few reports on its role in the toxic effects of arsenic exposure and the related mechanisms. Here, we show that the exposure of bronchial epithelial cells (BEAS-2B) to sodium arsenite promoted the activation of mTORC1 (p-mTORC1) and the inactivation of TFEB (p-TFEB), the number and activity of lysosomes decreased, the content of reduced glutathione (GSH) and superoxide dismutase (SOD) decreased, the content of malondialdehyde (MDA) increased, the DNA and chromosome damage elevated. Further, when mTORC1 was inhibited with RAPA, p-mTORC1 and p-TFEB down-regulated, GSH and SOD increased, MDA decreased, the DNA and chromosome damage reduced significantly, as compared with the control group. Our data revealed for the first time that mTORC1 - TFEB pathway was involved in sodium arsenite induced lysosomal alteration, oxidative stress and genetic damage in BEAS-2B cells, and it may be a potential intervention target for the toxic effects of arsenic.

Ecological and health risk assessment of heavy metals in soil and Chinese herbal medicines.

As medicinal plants can accumulate harmful metals from the native soil, people's consumption of these materials may cause the human body to accumulate toxic metal elements. This has given rise to people's concerns about the quality and safety of Chinese medicinal materials. This research aims to determine the levels of Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in four medicinal plant species (Aster tataricus L.f., Salvia miltiorrhiza Bge, Radix Aucklandiae, Scutellaria baicalensis Georgi) and their native soil. All samples were collected from Qian'an city, beside Yanshan Mountain Range in Tangshan city, east Hebei Province, north China. The contents of heavy metals we detected in the soil conformed to the current limits. However, the Cd and Hg in the soil had a very high potential ecological risk because of their contents higher than the base level of local soil. The contents of Cu, Cd, Hg and Pb in some medicinal herbs exceeded the standards. The content of Cu in Radix Aucklandiae exceeded the standard by 3 times, and others exceeded the standard by less than one time. The comprehensive health risk assessment of heavy metals with chronic non-carcinogenic effects for human body showed that none of the four medicinal herbs can create a health risk. Thus, there is no strong positive correlation between heavy metal pollution in medicinal herbs and that in the native soil. Further research should be investigated to the connection between the heavy metal levels in the soil and plants, and the comprehensive effects of soil, air and irrigation water on heavy metal pollution of Chinese herbal medicines. We also recommend that Chinese herbal medicines should be cultivated and gathered only from controlled or uncontaminated areas.

Clinicopathological characteristics and outcomes of 23 patients with secretory carcinoma of major salivary glands.

This retrospective study investigated the clinicopathological characteristics of secretory carcinoma of salivary glands (SCSG) in 23 patients with histopathologically confirmed SCSG between January 2010 and December 2020. In total, 13 males and 10 females (ratio, 1.3:1) aged 10 - 69 years (median, 45 years) were enrolled in this study; the average disease duration was 2.44 years (0.25-20 years). Twenty-one patients (91.3%) had SCSG in the parotid gland, and two (8.7%) in the submandibular gland. All patients had single nodules of diameters 0.8-4.8 cm (average 2.6 cm); five with lymph node metastases, and two with distant metastases. Immunohistochemically, tumors stained positive for S-100, mammaglobin, CK7, GATA3 and pan-Trk, and negative for DOG1, P63, and calponin, with Ki-67 positivity from 1 to 50%. ETV6 gene rearrangement was confirmed in 15 patients. All patients underwent oncological resection, four had radioactive particles implanted postoperatively, one received chemotherapy, and seven underwent chemoradiotherapy. Six patients had regional recurrences, two distant metastases, and one died before the last follow-up. SCSGs are typically indolent, with a low locoregional recurrence rate and excellent survival. Prognosis is correlated to clinical stage, pathological grade, and surgical procedures.

Metabolic reprogramming of normal oral fibroblasts correlated with increased glycolytic metabolism of oral squamous cell carcinoma and precedes their activation into carcinoma associated fibroblasts.

Cancers show a metabolic shift towards aerobic glycolysis. By "corrupting" their microenvironment, carcinoma cells are able to obtain energy substrates to "fuel" their mitochondrial metabolism and cell growth in an autophagy-associated, paracrine manner. However, the metabolic changes and role of normal fibroblasts in this process remain unclear. We devised a novel, indirect co-culture system to elucidate the mechanisms of metabolic coupling between stromal cells and oral squamous cell carcinoma (OSCC) cells. Here, we showed that normal oral fibroblasts (NOFs) and OSCC become metabolically coupled through several processes before acquiring an activated phenotype and without inducing senescence. We observed, for the first time, that NOFs export mitochondria towards OSCCs through both direct contact and via indirect mechanisms. NOFs are activated and are able to acquire a cancer-associated fibroblasts metabolic phenotype when co-cultivation with OSSC cells, by undergoing aerobic glycolysis, secreting more reactive oxygen species (ROS), high L-lactate and overexpressing lactate exporter MCT-4, leading to mitochondrial permeability transition pore (mPTP) opening, hypoxia, and mitophagy. On the other hand, Cav-1-low NOFs generate L-lactate to "fuel" mitochondrial metabolism and anabolic growth of OSCC. Most interestingly, the decrease in AMPK activity and PGC-1α expression might involve in regulation of ROS that functions to maintain final energy and metabolic homeostasis. This indicated, for the first time, the existence of ATP and ROS homeostasis during carcinogenesis. Our study suggests that an efficient therapeutical approach has to target the multiple mechanisms used by them to corrupt the normal surrounding stroma and metabolic homeostasis.

Fibroblasts rescue oral squamous cancer cell from metformin-induced apoptosis via alleviating metabolic disbalance and inhibiting AMPK pathway.

Metformin is an antidiabetic drug widely used for the treatment of type 2 diabetes. Growing evidence suggests that it may exert antitumor effects in vivo and in vitro. However, even with the promising potency on defeating cancer cells, the pre-clinical and epidemiological studies of metformin on various kinds of cancers are not satisfactory, and the reasons and underlying mechanisms remain unknown. Since cancer is a complex system, dependent on a promoting microenvironment, we hypothesize that the interactions between cancer cells and their neighborhood fibroblasts are essential for metformin resistance. To test this, we used a cell co-culture model closely mimicking the in vivo interactions and metabolic exchanges between normal stromal cells (NOFs) and oral squamous cancer cells (OSCC). Here we show that while metformin can significantly inhibit cell growth and induce apoptosis of OSCC cultured alone in a dose-dependent manner through activating p-AMPKT172 and modulating Bcl-2, Bax, and cleaved PARP. However, when OSCC are co-cultured with NOFs the metformin effects on OSCC cells are annihilated. NOFs are rescuing OSCC from metformin - induced apoptosis, at least partially, through inhibiting the activity of AMPK and PARP, maintaining mitochondrial membrane potential and increasing the oxidative stress. Our results indicate that metformin effects on oral cancer cells are modulated by the microenvironment and that this has to be taken into consideration in the context of developing a new combination of drugs for oral cancer treatment.

Factors to Consider When Deciding on the Type of Free-Flap Reconstruction of Head and Neck Soft Tissue Defects.

OBJECTIVES: The aim of the study was to evaluate the functional and aesthetic outcomes on donor and recipient sites and to determine the effects of technical factors including flap thickness and vessel diameters measured by ultrasonography as well as the size of the defect and postoperative volume reduction of the flaps measured by magnetic resonance imaging (MRI). METHODS: In patients who had undergone soft tissue reconstructive surgery between March 2013 and March 2016 using 55 anterolateral thigh flaps (ALTFs), 30 radial forearm flaps (RFFs), and 18 latissimus dorsi flaps (LDFs), color Doppler ultrasonography was performed to measure the thickness of the flap at the site of the perforator. Preoperative color Doppler ultrasound examinations of the blood vessel diameters of donor and recipient sites were carried out. RESULTS: 97.1% of flaps showed complete survival and 2.9% complete failure (2 ALTFs and 1 LDF). The difference in flap volume of ALTFs, RFFs, and LDFs between MRI 1 (3-6 weeks) and MRI 2 (6-18 months) was 27.6, 17.9, and 36.1%, respectively. CONCLUSION: Proper selection of the flap is important for the optimization of the aesthetic and functional outcomes. Ultrasound, the surgeon's experience and the extension and nature of the defect play a key role in the selection of the flap.

Myoepithelial Carcinoma of the Salivary Glands: A Clinicopathologic Study of 29 Patients.

PURPOSE: Myoepithelial carcinomas (MECs) of the salivary glands are relatively rare. The clinicopathologic features, immunohistochemical profile, and biologic behavior have not been well-defined. MATERIALS AND METHODS: A total of 29 patients with MEC diagnosed during a 10-year period were included in the present study focusing on the biologic behavior, and the pathologic samples of 28 patients were collected for additional investigation of the histologic characteristics. Thirteen samples with detailed immunohistochemical results were included for illustrating immunohistochemical profiles. RESULTS: The parotid gland (n = 7) was the most common site involved, followed by the palate (n = 6) and the submandibular gland (n = 6). A multinodular growth pattern (n = 14) and sheet-like arrangement of tumor cells (n = 14) were observed. Of the 28 MEC samples, 14 (50%) were epithelioid, 5 (18%) were clear cell, 5 (18%) were plasmacytoid, 3 (11%) were mixed cell type, and 1 (3%) was spindle. The tumor-associated matrix was more prevalently hyalinized than myxoid. Of the 28 cases, 12 (43%) were classified as high grade and 16 (57%) as low grade. Immunohistochemical analysis revealed pan-cytokeratin (92.3%), smooth muscle actin (36%), S-100 protein (54.5%), and p63 (91.7%) positivity and carcinoembryonic antigen (100%) negativity. Ki-67 was immunoreactive in 62% of the MECs, with the Ki-67 labeling index ranging from less than 5 to 20%. Eleven patients developed recurrence (median disease-free survival 43 months) and 11 (44%) developed metastases. Two patients (8%) died of disease after a mean period of 18 months. Fourteen patients (61%) were without any evidence of disease after a mean of 32.5 months (range 3 to 86). The mitotic rate correlated weakly (P = .042) with a poor outcome, but none of the other factors showed a significant correlation with the prognosis. CONCLUSION: MECs of the salivary glands have a relatively high recurrence rate and metastasis rate and a long period of survival with tumor. A combination of pathologic features and various immunohistochemical indexes are crucial for the accurate diagnosis of MECs. Extensive excision is the favorable choice for treating MECs, and suprahyoid lymph node dissection is recommended when the submandibular gland is involved.