Effects of marrow stromal cell-mediated microenvironment on human lung adenocarcinoma A549 cells

AIM: To investigate the effects of marrow stromal cell line HS-5 on human lung adenocarcinoma A549 cells in the tumor microenvironment. METHODS: The effects of HS-5 cell-conditioned medium (HS-5-CM) on the viability and migration ability of A549 cells were detected by MTT assay and wound-healing assay. After treatment with HS-5-CM, the expression of CX3C chemokine receptor 1 (CX3CR1) at mRNA level in the A549 cells was examined by qPCR. The protein levels of p-ERK and ERK in the A549 cells treated with MAPK/ERK pathway inhibitor U0126 were observed by Western blot, the migration ability of the A549 cells was measured by wound-healing assay, and the protein expression of CX3CR1 was determined by Western blot. RESULTS: HS-5-CM promoted the viability and migration ability of the A549 cells (P<0.01). The expression of CX3CR1 at mRNA level in the A549 cells was increased after treatment with HS-5-CM. MAPK/ERK inhibitor U0126 inhibited the activation of MAPK/ERK signaling pathway (P<0.01), and reduced the migration ability (P<0.01) and the expression of CX3CR1 (P<0.05) in the A549 cells. CONCLUSION: HS-5-CM significantly promotes the A549 cell viability and migration ability. Activation of MAPK/ERK signaling pathway and the expression of CX3CR1 may play a important role in this process.     

Mechanism of AKT1 negatively regulating breast cancer cell migration

AIM: To investigate the molecular mechanism and downstream signaling pathway by which AKT1 inhibition regulates breast cancer cell migration. METHODS: RNA interference was used to knockdown the expression of AKT1. Western blot assay was performed to examine the expression of AKT1 total protein, β-catenin total protein and β-catenin nuclear protein. Immunofluorescence was used to examine the cellular localization of β-catenin. Transwell assay was used to investigate whether β-catenin nuclear accumulation as an alternative pathway was responsible for breast cancer metastasis induced by AKT1 inhibition. RESULTS: The total protein expression of AKT1 was decreased in MCF-7 and MDA-MB-231 cells treated with AKT1 siRNA. A significant increase in the protein expression of β-catenin was observed in MCF-7 cells and MDA-MB-231 cells treated with AKT1 siRNA. Immunofluorescence staining showed that MCF-7 cells and MDA-MB-231 cells displayed strong β-catenin staining in the cytoplasm and nucleus after knockdown of AKT1 expression. The ability of tumor cell migration increased dramatically after treated with AKT1 specific siRNA in the breast cancer MCF-7 cells and MDA-MB-231 cells in Transwell assay. XAV-939 reversed breast cancer cell migration induced by knockdown of AKT1 expression. CONCLUSION: β-catenin nuclear accumulation contributes to AKT1 inhibition-mediated breast cancer cell migration.     

MicroRNA-126 enhances radiosensitivity of SGC-7901 cells via targeting inhibition of EZH2

AIM: To investigate the molecular biological mechanisms by which microRNA-126 (miR-126) enhances the radiosensitivity of gastric cancer cells. METHODS: SGC-7901 cells were cultured in vitro. In order to over-express miR-126 in SGC-7901 cells, miR-126 mimic was transfected. The mRNA and protein levels of enhancer of zeste ho-molog 2 (EZH2) were detected by RT-qPCR and Western blot, respectively. The targeting relationship between miR-126 and EZH2 was determined by dual-luciferase reporter assay. To estimate the effect of EZH2 on miR-126-enhanced radiosensitivity of the SGC-7901 cells, the pcDNA3.1-EZH2 vector was also co-transfected with miR-126 mimic, and then CCK-8 assay and flow cytometry were used to detect the viability and apoptotic rate of the cells after radiation. RESULTS: Over-expression of miR-126 significantly inhibited the expression of EZH2 in SGC-7901 cells both at protein and mRNA levels (P<0.05). A direct targeting relationship between miR-126 and EZH2 was confirmed by dual-luciferase reporter assay. Compared with the cells only transfected with miR-126 mimic, co-transfection of pcDNA3.1-EZH2 with miR-126 mimic increased the viability but reduced the apoptosis of the cells treated by radiation (P<0.05). CONCLUSION: Targeting inhibition of EZH2 may be one of the mechanisms by which miR-126 enhances the radiosensitivity of gastric cancer cells.     

Dietary intake of iodine‐enriched eggs decreases the incidence of mouse mammary tumors caused by the activated ErbB2 oncogene

Human epigenetic studies suggest that consumption of seaweed prevents mammary cancer, which possibly is explained by iodine daily intake. In this study, we evaluated the efficacy of dietary intake of iodine‐enriched eggs on mammary tumor incidence caused by the expression of activated type ErbB2. Female transgenic mice were divided into three groups, and fed a basic diet, a diet supplemented with ordinary eggs, or with iodine‐enriched eggs. The number of mammary tumors greater than 5 mm in diameter was recorded in mice at 6 months of age. We report that the average number of mammary tumors per mouse was significantly lower in the iodine‐enriched egg‐added diet group than in either the basic diet or ordinary egg diet groups. These results indicate that iodine intake through livestock‐derived products can reduce the incidence of mammary cancers caused by the expression of activated type ErbB2.     

Transcriptomic profile reveals molecular events associated to focal adhesion and invasion in canine mammary gland tumour cell lines

The prevalence of cancer in animals has increased significantly over the years. Mammary tumours are the most common neoplasia in dogs, in which around 50% are presented in the malignant form. Hence, the development and characterization of in vitro models for the study of canine tumours are important for the improvement of cancer diagnosis and treatment. Thus, the aim of this study was to characterize cell lines derived from canine mammary gland neoplasias which could be further used for basic and applied oncology research. Samples of canine mammary carcinomas were taken for cell culture and 2 cell lines were established and characterized in terms of cell morphology, tumourigenicity and global gene expression. Both cell lines presented spindle‐shape morphology and shown common malignant features as in vitro invasion potential and expression of epithelial and mesenchymal proteins. Also, we found gene expression patterns between the 2 cell cultures in comparison to the normal mammary gland tissue. Cells from M25 culture showed a higher invasion and in vivo tumourigenic potential, associated to the overexpression of genes involved in focal adhesion and extracellular matrix communication, such as FN1, ITGA8 and THBS2. The phenotypic characterization of these cells along with their global gene expression profile potentially determine new therapeutic targets for mammary tumours.     

Does the tumour microenvironment alter tumorigenesis and clinical response in transmissible venereal tumour in dogs?

The canine transmissible venereal tumour (CTVT) is a transmissible cancer that is spread naturally between dogs, with the ability to develop and evade the immune system, despite strict immune surveillance of the host. Furthermore, molecular signalling between cells of the immune system and the tumour microenvironment appear to influence the behaviour and development of the tumour. Thus, this study aimed to quantify the expression of genes related to the immune system such as IL‐6, IFN‐γ, and TGF‐β, as well as angiogenic factors (VEGF, CXCR4), in CTVT cells in vivo and in vitro (primary culture), correlating with the clinical response of the animals treated with vincristine. As expected, the most prevalent subtype was plasmacytoid cells, although lymphocytic cells were also found, indicating the possibility of polyclonality. When we compared the gene expressions of IFN‐γ and IL‐6, we mostly found low expression, concluding that MHC expression was probably not occurring in tumour cells, and no activation of immune cells to eliminate the tumour. The TGF‐β gene was normal in the majority of animals but demonstrated decreased expression in vincristine resistant animals, leading to the hypothesis that the concentration of tumour‐derived TGF‐β was affecting and even suppressing the real TGF‐β expression, favouring tumour proliferation and progression in these cases. VEGF expression was extremely high, demonstrating its angiogenic role in tumour growth, while CXCR4 was decreased, possibly because of CTVT’s low metastatic potential. Thus, we concluded that the tumour microenvironment, together with the immune system of the host, influences CTVT, presumably altering its tumorigenesis and the animal’s clinical response to treatment.     

Glycoproteomic profiling of serum peptides in canine lymphoma and transitional cell carcinoma

Differential expression of fucosylated glycoproteins has been correlated with malignancy and metastatic potential in various types of neoplasia. Utilizing glycoproteomics techniques, changes in fucosylated serum peptides associated with naturally occurring canine lymphoma and transitional cell carcinoma (TCC) have been evaluated. In both types of neoplasia, the majority of the fucosylated peptides that changed increased with the cancer. In one lymphoma case that was examined over the course of the disease, the same fucosylated peptides that increased during pre-chemotherapy decreased during post-chemotherapy, and then subsequently increased upon recurrence of the lymphoma. When comparing all the fucosylated peptides that increased in both types of cancer, there were only two peptides in common allowing discrimination between lymphoma and TCC based on their peptide profiles. These results emphasize the prospect of glycopeptide profiling in proteomics for use in discovering a panel of non-invasive, diagnostic or prognostic biomarkers of cancer.     

云南松松塔提取物对H22实体瘤小鼠模型的抑瘤作用

研究云南松松塔乙醇提取物(PEA)和碱水提取醇沉物(PED)对H22实体瘤小鼠的抑瘤作用。建立H22实体瘤小鼠模型,随机分组,灌胃给药,1次/d,给药10d。末次给药24h后,取血检测γ干扰素(IFN-γ)、白细胞介素-2(IL-2)、白细胞介素-4(IL-4)和白细胞介素-10(IL-10)含量;剥离肿瘤组织并称重,计算抑瘤率;检测肿瘤组织匀浆中环氧化酶-2(COX-2)和前列腺素E2(PGE2)含量;石蜡包埋HE染色观察肿瘤细胞病理组织学变化。结果显示,PEA和PED各剂量组小鼠平均肿瘤重量较模型组显著减小;最大抑瘤率分别达46.11%和58.05%。PEA和PED各剂量组小鼠外周血中IFN-γ和IL-2含量较模型组显著升高;IL-4和IL-10含量较模型组显著降低。PEA和PED各剂量组小鼠肿瘤组织中COX-2和PGE2含量较模型组显著减少;给药组正常肿瘤组织减少,有出血和坏死,脂肪组织增多。结果表明,PEA和PED可抑制H22实体瘤小鼠的肿瘤生长,其机制与调节Th1/Th2细胞平衡和抑制COX-2与PGE2的表达有关。     

Treatment of leiomyosarcoma in a tiger (Panthera tigris) with stereotactic radiotherapy

A 10‐year‐old male captive tiger (Panthera tigris) developed right‐sided facial asymmetry and enlargement. Computed tomography revealed a destructive mass of the right maxillary bone with right nasal cavity involvement. Histopathology indicated a spindle cell sarcoma. A single fraction of 22 Gy using stereotactic radiotherapy was prescribed. After treatment, the facial conformation returned to normal and the tiger resumed normal behavior. Diagnostics 4 months later indicated severe metastatic disease. Humane euthanasia and necropsy were performed. This is the first case utilizing stereotactic radiotherapy for the treatment of cancer in a tiger.