Microleakage Evaluation of Temporary Restorations Used in Endodontic Treatment-An Ex Vivo Study.

(1) Background: Coronal microleakage can lead to endodontic treatment failure. This study aimed to compare the sealing ability of different temporary restorative materials used during endodontic treatment. (2) Methods: Eighty sheep incisors were collected, uniformized in length, and access cavities were performed, except for in the negative control group, where the teeth were left intact. The teeth were divided into six different groups. In the positive control group, the access cavity was made and left empty. In the experimental groups, access cavities were restored with three different temporary materials (IRM®, Ketac™ Silver, and Cavit™) and with a definitive restorative material (Filtek Supreme™). The teeth were submitted to thermocycling, and two and four weeks later, they were infiltrated with 99mTcNaO4, and nuclear medicine imaging was performed. (3) Results: Filtek Supreme™ obtained the lowest infiltration values. Regarding the temporary materials, at two weeks, Ketac™ Silver presented the lowest infiltration, followed by IRM®, whereas Cavit™ presented the highest infiltration. At four weeks, Ketac™ Silver remained with the lowest values, whereas Cavit™ decreased the infiltration, comparable to IRM®. (4) Conclusion: Regarding temporary materials, Ketac™ Silver had the lowest infiltration at 2 and 4 weeks, whereas the highest infiltration was found in the Cavit™ group at two weeks and in the IRM® group at 4 weeks.

Investigating VEGF. miR-145-3p, and miR-101-3p Expression in Patients with Cholangiocarcinoma.

INTRODUCTION: Cholangiocarcinoma (CCA) is the second most common type of primary liver cancer. Several factors, such as epigenetic changes in promoter genes, gene expression, and microRNAs (miR), can contribute to genomic instability in cancer. This study aimed at evaluating the expression of VEGF, miRs 145-3p, and 101-3p in patients with CCA and their potential as biomarkers for diagnosis and prognosis of CCA. MATERIAL AND METHODS: Sixty two patients were studied. Out of these 62 patients, 41 cases had confirm CCA and 21 cases had hepatopathies complications. The RNA was extracted from a paraffined tissue block, and then the synthesis of cDNA was performed. The analysis of the expression of VEGF, miR-145-3p, and miR-101-3p was carried out by polymerase chain reaction in real time.  Results: The findings revealed that miRs 145-3p and 101-3p were under expressed in the case group compared to the control group (0.46; 0.17; P = 0.0001, respectively). VEGF was overexpressed in the case group compared to the control group (11.8; P = 0.0001). An increase in miR-145-3p expression level was observed in patients with perihilar CCA compared to those with distal CCA (0.51 ± 0.41; 0.17 ± 0.13; P = 0.0698). Survival rate analysis showed that 41.9% of patients with intrahepatic CCA and 31.5% of patients with extrahepatic CCA were free from death within 11 months, leading to a significant difference (P> 0.05). CONCLUSION: The underexpression of miRNAs, tumor suppressors, the overexpression of VEGF, smoking, and aging were associated with CCA based on our findings. It seems that the reduced expression of the studies miRNAs and increased expression of VEGF can contribute to a decrease in survival rate of patients with tumor in their intrahepatic bile ducts.

Iodine­131 metabolic radiotherapy leads to cell death and genomic alterations through NIS overexpression on cholangiocarcinoma.

Cholangiocarcinoma (CC) is an aggressive liver tumor with limited therapeutic options. Natrium­iodide symporter (NIS) mediates the uptake of iodine by the thyroid, representing a key component in metabolic radiotherapy using iodine­131 (131I) for the treatment of thyroid cancer. NIS expression is increased in CC, providing the opportunity for a novel therapeutic approach for this type of tumor. Thus, in this study, we aimed to evaluate therapeutic efficacy of 131I in two human CC cell lines. Uptake experiments analyzed the 131I uptake profiles of the tumor cell lines under study. The cells were irradiated with various doses of 131I to evaluate and characterize the effects of metabolic radiotherapy. NIS protein expression was assessed by immunofluorescence methods. Cell survival was evaluated by clonogenic assay and flow cytometry was used to assess cell viability, and the type of death and alterations in the cell cycle. The genomic and epigenetic characterization of both CC cells was performed before and after irradiation. NIS gene expression was evaluated in the CC cells by RT­qPCR. The results revealed that CC cells had a higher expression of NIS. 131I induced a decrease in cell survival in a dose­dependent manner. With the increasing irradiation dose, a decrease in cell viability was observed, with a consequent increase in cell death by initial apoptosis. Karyotype and array comparative genomic hybridization (aCGH) analyses revealed that both CC cell lines were near­triploid with several numerical and structural chromosomal rearrangements. NIS gene expression was increased in the TFK­1 and HuCCT1 cells in a time­dependent manner. On the whole, the findings of this study demonstrate that the presence of NIS in cholangiocarcinoma cell lines is crucial for the decreased cell viability and survival observed following the exposure of cholangiocarcinoma cells to 131I.

Targeting Hepatocellular Carcinoma: What did we Discover so Far?

Hepatocellular carcinoma (HCC) is increasingly considered an issue of global importance. Its rates of incidence and mortality have been markedly increasing over the last decades. Among risk factors, some should be highlighted, namely the infections by hepatitis B and C virus, as well as clinical cases of cirrhosis. HCC is characterized as asymptomatic disease in the initial stages which most often leads to a late diagnosis. At molecular and genetic level HCC represents a highly complex tumor entity, including a wide variety of mutations, thus accounting for different mechanisms of resistance towards therapeutic approaches. In particular, mutations of the TP53 gene, as well as a deregulation between the expression of pro- and anti-apoptotic proteins of the BCL-2 family are observed. Regarding treatment modalities, surgical procedures offer the best chance of cure, however, due to a late diagnosis, most of concerned patients cannot be subjected to them. Chemotherapy and radiotherapy are also ineffective, and currently, the treatment with sorafenib is the most commonly used systemic therapy although it can only increase the patient survival for some months. In this sense, a quick and accurate investigation is of utmost importance in order to develop ways of early diagnosis as well as new therapies for HCC.

New Approach for Treatment of Primary Liver Tumors: The Role of Quercetin.

Hepatocellular carcinoma (HCC) is the most common primary liver tumor (PLT), with cholangiocarcinoma (CC) being the second most frequent. Glucose transporter 1 (GLUT-1) expression is increased in PLTs and therefore it is suggested as a therapeutic target. Flavonoids, like quercetin, are GLUT-1 competitive inhibitors and may be considered as potential therapeutic agents for PLTs. The objective of this study was evaluation of quercetin anticancer activity in three human HCC cell lines (HepG2, HuH7, and Hep3B2.1-7) and in a human CC cell line (TFK-1). The possible synergistic effect between quercetin and sorafenib, a nonspecific multikinase inhibitor used in clinical practice in patients with advanced HCC, was also evaluated. It was found that in all the cell lines, quercetin induced inhibition of the metabolic activity and cell death by apoptosis, followed by increase in BAX/BCL-2 ratio. Treatment with quercetin caused DNA damage in HepG2, Hep3B2.1-7, and TFK-1 cell lines. The effect of quercetin appears to be independent of P53. Incubation with quercetin induced an increase in GLUT-1 membrane expression and a consequent reduction in the cytoplasmic fraction, observed as a decrease in (18)F-FDG uptake, indicating a GLUT-1 competitive inhibition. The occurrence of synergy when sorafenib and quercetin were added simultaneously to HCC cell lines was noticed. Thus, the use of quercetin seems to be a promising approach for PLTs through GLUT-1 competitive inhibition.

Quercetin in Cancer Treatment, Alone or in Combination with Conventional Therapeutics?

Cancer is a problem of global importance, since the incidence is increasing worldwide and therapeutic options are generally limited. Thus, it becomes imperative to find new therapeutic targets as well as new molecules with therapeutic potential for tumors. Flavonoids are polyphenolic compounds that may be potential therapeutic agents. Several studies have shown that these compounds have a higher anticancer potential. Among the flavonoids in the human diet, quercetin is one of the most important. In the last decades, several anticancer properties of quercetin have been described, such as cell signaling, pro-apoptotic, anti-proliferative and anti-oxidant effects, growth suppression. In fact, it is now well known that quercetin has diverse biological effects, inhibiting multiple enzymes involved in cell proliferation, as well as, in signal transduction pathways. On the other hand, there are also studies reporting potential synergistic effects when combined quercetin with chemotherapeutic agents or radiotherapy. In fact, several studies which aim to explore the anticancer potential of these combined treatments have already been published, the majority with promising results. Actually it is well known that quercetin can act on the chemosensitization and radiosensitization but also as chemoprotective and radioprotective, protecting normal cells of the side effects that results from chemotherapy and radiotherapy, which obviously provides notable advantages in their use in anticancer treatment. Thus, all these data indicate that quercetin may have a key role in anticancer treatment. In this context, this review is focused on the relationship between flavonoids and cancer, with special emphasis on the role of quercetin.

Chiral 6,7-bis(hydroxymethyl)-1H,3H-pyrrolo[1,2-c]thiazoles with anti-breast cancer properties.

The synthesis and biological evaluation of 6,7-bis(hydroxymethyl)-1H,3H-pyrrolo[1,2-c]thiazoles as anticancer agents against MCF7 breast cancer cell lines is reported. The design of the new compounds has been guided considering (3R)-6,7-bis(hydroxymethyl)-5-methyl-3-phenyl-1H,3H-pyrrolo[1,2-c]thiazole as the lead compound due to its good performance against MCF7 breast cancer cell lines (IC(50) = 1.0 µM). The structural changes included the removal of the phenyl group at C-3, the replacement of this group by a 3,4,5-trimethoxyphenyl group, the removal of the methyl group at C-5 from the lead scaffold and the replacement of this group by a phenyl substituent. Overall, these studies showed that the combined presence of a phenyl group at C-3 and a methyl group at C-5 in the 1H,3H-pyrrolo[1,2-c]thiazole ring system is essential to ensure high cytotoxicty against MCF7 breast cancer cell lines. To probe whether the absolute configuration of the lead compound might affect the anticancer activity, its enantiomer was prepared and the activity against MCF7 cells was evaluated. (3S)-6,7-Bis(hydroxymethyl)-5-methyl-3-phenyl-1H,3H-pyrrolo[1,2-c]thiazole proved to be the most active compound so far studied, with IC(50) value of 0.5 µM.

Chiral 6-hydroxymethyl-1H,3H-pyrrolo[1,2-c]thiazoles: novel antitumor DNA monoalkylating agents.

New chiral 1H,3H-pyrrolo[1,2-c]thiazoles were synthesized and screened for their in vitro activity as anti-cancer agents in three human tumor cell lines, colorectal adenocarcinoma, melanoma and breast adenocarcinoma. (R)-6-Hydroxymethyl-5-methyl-3-phenyl-1H,3H-pyrrolo[1,2-c]thiazole and the corresponding benzylcarbamate showed selectivity for breast cancer cell lines with IC(50) values of 2.4 microM and 2.2 microM, respectively. The latter also showed significant activity against colorectal adenocarcinoma cancer cell lines (IC(50) = 8.7 microM). In contrast, the 7-hydroxymethyl-5-methyl-3-phenyl-1H,3H-pyrrolo[1,2-c]thiazole gave moderate anti-cancer activity. The performance against breast cancer cell lines (IC(50) = 1.0 microM) of a potential bisalkylating agent, a (3R)-6,7-bis(hydroxymethyl)-1H,3H-pyrrolo[1,2-c]thiazole, wasn't significantly different from the one observed for the monoalkylating derivatives indicating that the main mechanism of action may in fact be the monoalkylation process.