Isolation and phenotypic characterization of cancer stem cells from metastatic oral cancer cells.

OBJECTIVES: To isolate cancer stem cells (CSC) from a metastatic oral squamous cell carcinoma (OSCC) cell line and investigate their in vitro and in vivo phenotypic characteristics. MATERIALS AND METHODS: Subpopulations with individual staining intensities for CD44 and CD326 were isolated from the OSCC cell line LN-1A by FACS: CD44Low/CD326- (CSC-M1), CD44Low/CD326High (CSC-E), and CD44High/CD326- (CSC-M2). Proliferation, clonogenic potential, adhesion, migration, epithelial-mesenchymal transition markers, and sensitivity to cisplatin and TVB-3166 were analyzed in vitro. Tumor formation and metastasis were assessed by subcutaneous and orthotopic inoculations into BALB/c mice. RESULTS: E-cadherin levels were higher in CSC-E cells while vimentin and Slug more produced by CSC-M2 cells. CSC-M1 and CSC-M2 subpopulations showed higher proliferation, produced more colonies, and have stronger adhesion to the extracellular matrix. All cell lines established tumors; however, CSC-E and CSC-M2 formed larger masses and produced more metastases. CONCLUSION: The CSC subpopulations here described show increased cancer capabilities in vitro, tumorigenic and metastatic potential in vivo, and may be exploited in the search for novel therapeutic targets for OSCC.

Blocking lipid synthesis induces DNA damage in prostate cancer and increases cell death caused by PARP inhibition.

Androgen deprivation therapy (ADT) is the primary treatment for prostate cancer; however, resistance to ADT invariably develops, leading to castration-resistant prostate cancer (CRPC). Prostate cancer progression is marked by increased de novo synthesis of fatty acids due to overexpression of fatty acid synthase (FASN), making this enzyme a therapeutic target for prostate cancer. Inhibition of FASN results in increased intracellular amounts of ceramides and sphingomyelin, leading to DNA damage through the formation of DNA double-strand breaks and cell death. We found that combining a FASNi with the poly-ADP ribose polymerase (PARP) inhibitor olaparib, which induces cell death by blocking DNA damage repair, resulted in a more pronounced reduction in cell growth than that caused by either drug alone. Human CRPC organoids treated with a combination of PARP and FASNi were smaller, had decreased cell proliferation, and showed increased apoptosis and necrosis. Together, these data indicate that targeting FASN increases the therapeutic efficacy of PARP inhibitors by impairing DNA damage repair, suggesting that combination therapies should be explored for CRPC.

Discovery proteomics reveals potential protein signature associated with malignant phenotype acquisition in pleomorphic adenoma.

OBJECTIVE: To analyze the proteomic profile of salivary pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma (CXPA) samples and correlate them with the malignant transformation of the PA. MATERIALS AND METHODS: Thirty samples (10 PA, 16 CXPA, and 4 residual PA) were microdissected and submitted to liquid chromatography-tandem mass spectrometry (LC-MS/MS). The proteomic data and protein identification were analyzed through LC-MS/MS spectra using the MaxQuant software. RESULTS: The proteomic analysis identified and quantified a total of 240 proteins in which 135 were found in PA, residual PA, and CXPA. The shared proteins were divided into six subgroups, and the proteins that showed statistically significant differences (p > 0.05) and fold-change > or <2.5 in one subgroup to another subgroup were included. Seven proteins (Apolipoprotein A-I-APOA1, haptoglobin-HP, protein of the synaptonemal complex 1-SYCP1, anion transport protein of band 3-SLC4A1, subunit µ1 of AP-1 complex-AP1M1, beta subunit of hemoglobin-HBB, and dermcidin-DCD) were classified as potential protein signatures, being HP, AP1M1, and HBB with higher abundance for PA to residual PA, APOA1 with higher abundance for PA to CXPA, SLC4A1 with lower abundance in the PA to CXPA, SYCP1with lower abundance for residual PA to CXPA, and DCD with higher abundance in the CXPA with epithelial differentiation to myoepithelial differentiation. CONCLUSIONS: In this work, we demonstrated the comparative proteomic profiling of PA, residual PA, and CXPA, and seven were proposed as protein signatures, some of which may be associated with the malignant phenotype acquisition.

FASN inhibition sensitizes metastatic OSCC cells to cisplatin and paclitaxel by downregulating cyclin B1.

OBJECTIVES: To investigate the potential effect of fatty acid synthase (FASN) inhibitor orlistat to enhance the effectiveness of chemotherapy drugs widely used to treat oral squamous cell carcinomas (OSCC), such as 5-fluorouracil, cisplatin, and paclitaxel. METHODS: The OSCC SCC-9 LN-1 metastatic cell line, which expresses high levels of FASN, was used for drug combination experiments. Cell viability was analyzed by crystal violet staining and automatic cell counting. Apoptosis and cell cycle were analyzed by flow cytometry with Annexin-V/7-AAD and propidium iodide staining, respectively. Cyclin B1, Cdc25C, Cdk1, FASN, and ERBB2 levels were assessed by Western blotting. Finally, cell scratch and transwell assays were performed to assess cell migration and invasion. RESULTS: Inhibition of FASN with orlistat sensitized SCC-9 LN-1 cells to the cytotoxic effects of paclitaxel and cisplatin, but not 5-fluorouracil, which was accompanied by a significant reduction in cyclin B1. The suppression of proliferation, migration, and invasion of SCC-9 LN-1 cells induced by orlistat plus cisplatin or paclitaxel was not superior to the effects of chemotherapy drugs alone. CONCLUSION: Our results suggest that orlistat enhances the chemosensitivity of SCC-9 LN-1 cells to cisplatin and paclitaxel by downregulating cyclin B1.

Pharmacological fatty acid synthase inhibitors differently affect the malignant phenotype of oral cancer cells.

OBJECTIVE: Fatty acid synthase levels are associated with aggressiveness, prognosis, and risk of metastasis in oral squamous cell carcinomas. This enzyme contains seven catalytic domains and its inhibition by synthetic or natural drugs has antineoplastic properties such as C75, which is a synthetic inhibitor of the ß- ketoacyl synthase domain, the antibiotic triclosan, ligand of the enoyl reductase domain, and the antiobesity drug orlistat, which inhibits the thioesterase domain. Here, we sought to investigate and compare the in vitro effects of C75, triclosan, and orlistat on malignant phenotypes of the cell line SCC-9: proliferation, cell cycle, apoptosis, adhesion, migration, and invasion. DESIGN: Half-maximal inhibitory concentration (IC50) was determined using cell viability assays. Cell death and cell cycle progression were analyzed by Annexin V-PE/7-ADD-PerCP labeling and propidium iodide staining, respectively. Cell migration and invasion were assayed by transwells assays and cell adhesion using collagen and fibronectin. RESULTS: C75 showed the lowest IC50 and higher inhibition of lipid droplets at low concentrations and reduced cell motility. Triclosan showed the intermediate IC50 value, excellent reduction of lipid bodies at the IC50 when compared with C75 and orlistat. Also, triclosan reduced cell cycle progression, adhesion, migration, and invasion of SCC-9 and induced the highest levels of apoptosis. Orlistat promoted cell cycle arrest, but showed the lowest induction of apoptosis and did not affected invasion and adhesion of SCC-9. CONCLUSION: Altogether, despite the particular effects of the analyzed fatty acid synthase inhibitors, triclosan showed to better interfere in tumorigenic phenotypes of SCC-9 cells.

Stanniocalcin 2 contributes to aggressiveness and is a prognostic marker for oral squamous cell carcinoma.

Stanniocalcin 2 (STC2), a glycoprotein that regulates calcium and phosphate homeostasis during mineral metabolism, appears to display multiple roles in tumorigenesis and cancer progression. This study aimed to access the prognostic value of STC2 in oral squamous cell carcinoma (OSCC) and its implications in oral tumorigenesis. STC2 expression was examined in 2 independent cohorts of OSCC tissues by immunohistochemistry. A loss-of-function strategy using shRNA targeting STC2 was employed to investigate STC2 in vitro effects on proliferation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT) and possible activation of signaling pathways. Moreover, STC2 effects were assessed in vivo in a xenograft mouse cancer model. High expression of STC2 was significantly associated with poor disease-specific survival (HR: 2.67, 95% CI: 1.37-5.21, p = 0.001) and high rate of recurrence with a hazard ratio of 2.80 (95% CI: 1.07-5.71, p = 0.03). In vitro downregulation of STC2 expression in OSCC cells attenuated proliferation, migration and invasiveness while increased apoptotic rates. In addition, the STC2 downregulation controlled EMT phenotype of OSCC cells, with regulation on E-cadherin, vimentin, Snail1, Twist and Zeb2. The reactivation of STC2 was observed in the STC2 knockdown cells in the in vivo xenograft model, and no influence on tumor growth was observed. Modulation of STC2 expression levels did not alter consistently the phosphorylation status of CREB, ERK, JNK, p38, p70 S6K, STAT3, STAT5A/B and AKT. Our findings suggest that STC2 overexpression is an independent marker of OSCC outcome and may contribute to tumor progression via regulation of proliferation, survival and invasiveness of OSCC cells.

Anticancer properties of the fatty acid synthase inhibitor TVB-3166 on oral squamous cell carcinoma cell lines.

OBJECTIVE: Fatty acid synthase (FASN) is overexpressed in several human cancers, including oral squamous cell carcinoma (OSCC). TVB-3166 is a recently described FASN inhibitor with antitumor effects and potential clinical relevance. The objective of this study was to evaluate the effects of TVB-3166 on OSCC cell lines. MATERIALS AND METHODS: The OSCC cell line SCC-9 modified to express ZsGreen (ZsG) (SCC-9 ZsG) and its in vivo selected metastatic derivative LN-1A were used to evaluate anticancer properties of TVB-3166. Cell viability was determined using MTT assays and proliferation determined by cell counting in a Neubauer chamber. Cell death and cell cycle progression were analyzed by Annexin V-PE/7-ADD-PerCP labeling and PI staining, respectively. Cell migration was assayed by scratch assays and cell adhesion using myogel. Production of FASN, p-AKT, CPT1-α, and epithelial-mesenchymal transition (EMT) markers were examined by Western blotting. RESULTS: TVB-3166 significantly reduced cell viability and proliferation, promoted cell cycle arrest and apoptosis, and increased adhesion to myogel in both OSCC cell lines. Finally, the drug reduced SCC-9 ZsG migration. CONCLUSION: Our results demonstrated that TVB-3166 has anticancer effects on both SCC-9 ZsG and its metastatic version LN-1A, which are worthy of investigation in preclinical models for OSCC.

Gene and immunohistochemical expression of HIF-1α, GLUT-1, FASN, and adipophilin in carcinoma ex pleomorphic adenoma development.

OBJECTIVE: To analyze the gene and immunohistochemical expression of HIF-1α, GLUT-1, FASN, and adipophilin in normal salivary gland (NSG), pleomorphic adenoma (PA), and carcinoma ex pleomorphic adenoma (CXPA) samples. MATERIAL AND METHODS: The gene expression was investigated by the real-time PCR (qRT-PCR) method in 9 samples of frozen tissues of normal salivary gland, 13 PA, and 10 CXPA. We validated the reactions by immunohistochemistry on 20 samples from NSG, 85 PA, and 44 CXPA. RESULTS: Our results showed that there was no statistically significant difference in HIF-1α gene and immunohistochemistry expression among the tissues studied while FASN gene and immunohistochemistry expression increased along the carcinogenesis of the PA. GLUT-1 was significantly more expressed in tumor tissues (PA and CXPA), although protein is mainly expressed in transformed cells than in PA and NSG. In contrast, adipophilin was significantly more expressed in NSG while the expression of the protein increased in PA and CXPA. CONCLUSIONS: In summary, the data presented here suggest that neoplastic cells reprogram the expression of GLUT-1 and adipophilin to adapt to the tumor microenvironment and reinforce, through immunohistochemical results, a possible transcriptional and post-translational regulatory mechanisms that act on the expression of these genes.

Suppression of MAGE-A10 alters the metastatic phenotype of tongue squamous cell carcinoma cells.

MAGE-A10 is a member of the MAGE protein family (melanoma associated antigen) which is overexpressed in cancer cells. Although MAGE-A10 has been characterized for some time and is generally associated to metastasis its function remains unknown. Here we describe experiments using as models oral squamous cell carcinoma (OSCC) cell lines displaying increasing metastatic potential (LN1 and LN2). These cell lines were transduced with lentivirus particles coding for short hairpin against MAGE-A10 mRNA. Repression of MAGE-A10 expression in LN2 cells altered their morphology and impaired growth of LN1 and LN2 cell lines. Furthermore, repression of MAGE-A10 expression increased cell-cell and cell matrix adhesion. Furthermore shMAGEA10 cells were shown to assemble aberrantly on a 3D culture system (microspheroids) when compared to cells transduced with the control scrambled construct. Cell migration was inhibited in knocked down cells as revealed by two different migration assays, wound healing and a phagokinetic track motility assay. In vitro invasion assay using a leiomyoma tissue derived matrix (myogel) showed that shMAGEA10 LN1 and shMAGEA10 LN2 cells displayed a significantly diminished ability to penetrate the matrices. Concomitantly, the expression of E-cadherin, N-cadherin and vimentin genes was analyzed. shMAGEA10 activated the expression of E-cadherin and repression N-cadherin and vimentin transcription. Taken together the results indicate that MAGE-A10 exerts its effects at the level of the epithelial-mesenchymal transition (EMT) presumably by regulating the expression of adhesion molecules.

Tooth Loss Related to Root Perforation: Legal Approach in Endodontic Practice / Perdida Dentaria Relacionada con una Perforación Radicular: Una Visión Legal en la Práctica Endodóntica

Most of the techniques used in endodontic treatment are limited to the internal space to the tooth, avoiding reaching the periapical region. However, some accidents can happen, such as fracture of endodontic instruments, perforation, leakage of material, tooth fracture among others, depending on the complexityof each case. The aim of this study was to report a case involving a tooth loss caused by root perforation. In this case, the patient filed a lawsuit against the former professional who had performed endodontic treatment requiring compensation for moral and material damages. In conclusion, the practice endodontic the clarification of the risks is crucial, considering the particularities of each case. Thus, it is suggested that the verbal and written information should be offered to patients.

La mayoría de las técnicas usadas en el tratamiento de endodoncia son limitadas hacia la cavidad dentinaria pulpar coronal y el canal radicular, evitándose alcanzar la región periapical alveolar. Sin embargo, algunos accidentes pueden ocurrir, tales como: fracturas de instrumentos de endodoncia, perforaciones radiculares, extravasación del material de obturación y fracturas dentarias entre otros. Cada uno involucra una respectiva complejidad. El objetivo de esta publicación fue reportar un caso donde ocurrió la pérdida de un diente permanente causado por una perforación radicular. En este caso la paciente presentó una demanda contra el profesional quién realizó el tratamiento de endodoncia, solicitando una compensación por daños morales y materiales. Se concluye que en la práctica de endodoncia, la especificación de los riesgos es crucial, considerándose las particularidades de cada caso. Así, se sugiere que una buena información verbal y escrita deberá ser proporcionada al paciente.