Caroline Brandi Schlaepfer Sales

Altered expression of cytokeratins in primary, recurrent and syndrome keratocystic odontogenic tumors.

Keratocystic odontogenic tumor (KOT) is a benign cystic tumor that affects the jaw bones and may be associated with the nevoid basal cell carcinoma syndrome (NBCCS). Twenty-five cases diagnosed as KOT, including primary and recurrent tumors and those associated with NBCCS, were submitted to immunohistochemical study for analysis of cytokeratins (CKs) 7, 8, 10, 13, 14, 18 and 19. The results showed CK13 immunostained on the intermediate layers and upper cells. CK14 was expressed in all epithelial layers and in those areas where inflammation and subepithelial splits were present; this protein was preserved within the basal cells. CK 18 was expressed mainly in the basal layer, whereas CK19 was expressed mainly on the intermediate and superficial layers. The remaining CKs tested were not immuoreactive. The status of maturation of cytokeratin seems to be altered on KOTs, and this is not distinct when different tumors are compared.

Novel piplartine-containing ruthenium complexes: synthesis, cell growth inhibition, apoptosis induction and ROS production on HCT116 cells

Piplartine (piperlongumine) is a plant-derived molecule that has been receiving intense interest due to its anticancer characteristics that target the oxidative stress. In the present paper, two novel piplartine-containing ruthenium complexes [Ru(piplartine)(dppf)(bipy)](PF6)2 (1) and [Ru(piplartine)(dppb)(bipy)](PF6)2 (2) were synthesized and investigated for their cellular and molecular responses on cancer cell lines. We found that both complexes are more potent than metal-free piplartine in a panel of cancer cell lines on monolayer cultures, as well in 3D model of cancer multicellular spheroids formed from human colon carcinoma HCT116 cells. Mechanistic studies uncovered that the complexes reduced the cell growth and caused phosphatidylserine externalization, internucleosomal DNA fragmentation, caspase-3 activation and loss of the mitochondrial transmembrane potential on HCT116 cells. Moreover, the pre-treatment with Z-VAD(OMe)-FMK, a pan-caspase inhibitor, reduced the complexes-induced apoptosis, indicating cell death by apoptosis through caspase-dependent and mitochondrial intrinsic pathways. Treatment with the complexes also caused a marked increase in the production of reactive oxygen species (ROS), including hydrogen peroxide, superoxide anion and nitric oxide, and decreased reduced glutathione levels. Application of N-acetyl-cysteine, an antioxidant, reduced the ROS levels and apoptosis induced by the complexes, indicating activation of ROS-mediated apoptosis pathway. RNA transcripts of several genes, including gene related to the cell cycle, apoptosis and oxidative stress, were regulated under treatment. However, the complexes failed to induce DNA intercalation. In conclusion, the complexes are more potent than piplartine against different cancer cell lines and are able to induce caspase-dependent and mitochondrial intrinsic apoptosis on HCT116 cells by ROS-mediated pathway.

Elevated VEGFA mRNA levels in oral squamous cell carcinomas and tumor margins: a preliminary study

BACKGROUND New blood vessel formation events are essential for tumor clonal expansion and progression. Despite the importance of vascular endothelial growth factor A (VEGFA) for tumor angiogenesis, few studies have evaluated the expression profile of this gene in oral squamous cell carcinoma (OSCC) and tumor margins (TM). This study aimed to evaluate the expression of the VEGFA gene and its protein in OSCC and TM. METHODS Gene expression was evaluated in cryopreserved samples of OSCCs (n = 44), TM (n = 7), and normal mucosa from healthy patients (n = 3; NM). Quantitative PCRs were performed using the TaqMan system for the VEGFA gene, and gene expression was determined using the 2(-∆∆CQ) method. For immunohistochemical evaluation, 27 OSCC samples were embedded in a tissue microarray (TMA) block and reactions were performed using the Advance system. RESULTS VEGFA transcript levels were 1.7-fold higher in OSCC than in NM samples. VEGFA mRNA was overexpressed in TM samples compared to NM (3.4-fold) and OSCC (2.0-fold) samples. VEGFA transcript level was overexpressed in T3-T4 tumors, metastatic lymph nodes, and stage III-IV OSCCs. Immunoreactivity of the VEGFA protein was detected in the cytoplasm of parenchymal and stromal cells, mainly in endothelial cells and fibroblasts. CONCLUSION Our results show that VEGFA was overexpressed in aggressive OSCCs and that VEGFA expression may be an important prognostic factor in this type of cancer. Finally, tumor margins may be involved in the production of angiogenic molecules.

A novel ruthenium complex with xanthoxylin induces S-phase arrest and causes ERK1/2-mediated apoptosis in HepG2 cells through a p53-independent pathway

Ruthenium-based compounds have gained great interest due to their potent cytotoxicity in cancer cells; however, much of their potential applications remain unexplored. In this paper, we report the synthesis of a novel ruthenium complex with xanthoxylin (RCX) and the investigation of its cellular and molecular action in human hepatocellular carcinoma HepG2 cells. We found that RCX exhibited a potent cytotoxic effect in a panel of cancer cell lines in monolayer cultures and in a 3D model of multicellular cancer spheroids formed from HepG2 cells. This compound is detected at a high concentration in the cell nuclei, induces DNA intercalation and inhibits DNA synthesis, arresting the cell cycle in the S-phase, which is followed by the activation of the caspase-mediated apoptosis pathway in HepG2 cells. Gene expression analysis revealed changes in the expression of genes related to cell cycle control, apoptosis and the MAPK pathway. In addition, RCX induced the phosphorylation of ERK1/2, and pretreatment with U-0126, an MEK inhibitor known to inhibit the activation of ERK1/2, prevented RCX-induced apoptosis. In contrast, pretreatment with a p53 inhibitor (cyclic pifithrin-α) did not prevent RCX-induced apoptosis, indicating the activation of a p53-independent apoptosis pathway. RCX also presented a potent in vivo antitumor effect in C.B-17 SCID mice engrafted with HepG2 cells. Altogether, these results indicate that RCX is a novel anticancer drug candidate.

MCM3: A Novel Proliferation Marker in Oral Squamous Cell Carcinoma.

The present study sought to evaluate and compare the immunoexpression of proteins minichromosome maintenance (MCM) 3 and Ki-67 in oral squamous cell carcinoma (OSCC) to assess the potential of these proteins as markers of cellular proliferation. Twenty-eight cases of OSCC, 9 of tumor-free resection margins (TM), and 4 of non-neoplastic oral mucosa (NNM) were subjected to immunohistochemistry to detect the expression of proteins MCM3 and Ki-67. All OSCCs demonstrated positivity for both proteins. In these tumors, greater MCM3 immunoreactivity was observed in comparison with Ki-67, whereas TMs and NNMs exhibited greater Ki-67 expression compared with MCM3. The immunoexpression of Ki-67 seemed to be influenced by the inflammatory process, particularly in TM and NNM. Our findings indicate that although both MCM3 and Ki-67 represent reliable markers of cellular proliferation in OSCC, as MCM3 expression does not appear to be influenced by external factors, this protein may emerge as a novel marker of cellular proliferation in these types of tumors.

Anti-liver cancer activity in vitro and in vivo induced by 2-pyridyl 2,3-thiazole derivatives

&NA; A total of 24 hybrid compounds containing pyridyl and 1,3‐thiazole moieties were screened against HL‐60 (leukemia), MCF‐7 (breast adenocarcinoma), HepG2 (hepatocellular carcinoma), NCI‐H292 (lung carcinoma) human tumor cell lines and non‐tumor cells (PBMC, human peripheral blood mononuclear cells). Most of them were highly potent in at least one cell line tested (IC50 ≤ 3 &mgr;M), being HL‐60 the most sensitive and HepG2 the most resistant cell line. Among them, TAP‐07 and TP‐07 presented cytotoxic activity in all tumor cell lines, including HepG2 (IC50 2.2 and 5.6 &mgr;M, respectively) without antiproliferative effects to normal cells (PBMC) (IC50 > 30 &mgr;M), making TAP‐07 and TP‐07, the compounds with the most favorable selectivity index. TAP‐07 and TP‐07 induced apoptosis in HepG2 cells and presented in vivo antitumor activity in hepatocellular xenograft cancer model in C.B‐17 severe combined immunodeficient mice. Systemic toxicological verified by biochemical and histopathological techniques reveled no major signs of toxicity after treatment with TAP‐07 and TP‐07. Together the results indicated the anti‐liver cancer activity of 2‐pyridyl 2,3‐thiazole derivatives. Highlights2‐Pyridyl 2,3‐thiazole derivatives induce selective cytotoxicity to cancer cell lines.2‐Pyridyl 2,3‐thiazole derivatives cause cell death by apoptosis in HepG2 cells.2‐Pyridyl 2,3‐thiazole derivatives inhibit the progression of xenograft HepG2 liver cancer in SCID mice.2‐Pyridyl 2,3‐thiazole derivatives present no major signs of toxicity.

β-Lapachone and its iodine derivatives cause cell cycle arrest at G2/M phase and reactive oxygen species-mediated apoptosis in human oral squamous cell carcinoma cells

Abstract &bgr;‐Lapachone is a natural naphthoquinone originally obtained from the bark of the purple Ipe (Tabebuia avellanedae Lor, Bignoniaceae) and its therapeutic potential in human cancer cells has been evaluated in several studies. In this study, we examined the effects of &bgr;‐lapachone and its 3‐iodine derivatives (3‐I‐&agr;‐lapachone and 3‐I‐&bgr;‐lapachone) on cell proliferation, cell death, and cancer‐related gene expression in human oral squamous cell carcinoma cells. &bgr;‐Lapachone and its 3‐iodine derivatives showed potent cytotoxicity against different types of human cancer cell lines. Indeed, treatment with these compounds induced cell cycle arrest at G2/M phase, followed by internucleosomal DNA fragmentation, and caused significant increases in phosphatidylserine externalization, caspase‐8 and ‐9 activation, mitochondrial membrane depolarization, reactive oxygen species (ROS) production, and apoptotic cell death morphology. The apoptosis induced by the compounds was prevented by pretreatment with a pan‐caspase inhibitor (Z‐VAD‐FMK) and an antioxidant (N‐acetyl‐l‐cysteine). In vivo, &bgr;‐lapachone and its 3‐iodine derivatives significantly reduced tumor burden and did not alter any of the biochemical, hematological, or histological parameters of the animals. Overall, &bgr;‐lapachone and its 3‐iodine derivatives showed promising cytotoxic activity due to their ability to induce cell cycle arrest at G2/M phase and promote caspase‐ and ROS‐mediated apoptosis. In addition, &bgr;‐lapachone and its 3‐iodine derivatives were able to suppress tumor growth in vivo, indicating that these compounds may be new antitumor drug candidates. Graphical abstract Figure. No caption available. Highlights&bgr;‐Lapachone and its 3‐iodine derivatives induce apoptosis in human OSCC cells.&bgr;‐Lapachone and its 3‐iodine derivatives increase ROS levels in human OSCC cells.&bgr;‐Lapachone and its 3‐iodine derivatives reduce cell growth in a xenograft model.

Enhanced Expression of Hedgehog Pathway Proteins in Oral Epithelial Dysplasia.

The aim of this study was to characterize the profile of the proteins involved in the Hedgehog signaling pathway to aid in the understanding of the pathogenesis of oral epithelial dysplasia (OED). The proteins SHH, PTCH1, HHIP, SUFU, GLI1, and cyclin D1 were evaluated by immunohistochemistry in 25 cases of OED, 4 of non-neoplasic oral mucosa, 8 of inflammatory fibrous hyperplasia and 5 of hyperkeratosis. SHH proteins were predominant in OED cases. Although PTCH1 protein was observed in all cases, this molecule was more highly expressed in OED. The inhibitor protein SUFU was present in OED and HHIP protein was overexpressed in OED. GLI1 proteins were predominantly found in the nuclei of epithelial cells in OED. Basal and suprabasal cells in the epithelial lining were positive for cyclin D1 only in OED. In conclusion, comparative analysis of the proteins involved in the Hedgehog pathway suggests that enhanced expression of these proteins can play an important role in the biological behavior of OED.

Evaluation of Mast Cell Density in the Tumor Microenvironment in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

The objective of this study was to compare mast cell density (MCD) in oral epithelial dysplasias (OED) and oral squamous cell carcinoma (OSCC) and determine its correlation with clinical and histopathologic parameters and the degree of tumor differentiation. Thirty OSCC samples, 14 OED samples, and 4 non-neoplastic oral mucosa samples were analyzed by immunohistochemistry to determine MCD based on the expression of MC tryptase. In addition, MCs were categorized morphologically into degranulated and granulated cells. MCD was significantly higher in OSCC lesions with a greater degree of differentiation (P=0.04). No significant difference in MCD was detected between mild and moderate OED samples (P=0.09). Our findings indicate that MCs are present in the tumor microenvironment and may be associated with a better prognosis.