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EN
Breast cancer is the most common malignant cancer among women. Both drug resistance and metastasis are major problems in the treatment of breast cancer. Therefore, adjuvant therapy may improve patients’ survival and affect their quality of life. It is suggested that epigallocatechin gallate (EGCG) which is well known for its chemopreventive activity and acts on numerous molecular targets may inhibit the growth and metastasis of some cancers. Hence, discovering the metastatic molecular mechanisms for breast cancer may be useful for therapy.The aim of the study was to determine the effect of EGGC on the mRNA expression level of genes such as ZEB1, ABCB1, MDM2, TWIST1 and PTEN in MCF-7 breast cancer cells. MCF7/DOX were cultured in the presence of 0.2 μM DOX and EGCG (20-50 μM). The mRNA expression level was determined by real-time quantitative PCR using RealTime ready Custom Panel 96 kit. Our results showed an important increase (about 2-fold for 20 μM EGCG + 0.2 μM DOX and 2.5-fold for 50 μM EGCG + 0.2 μM DOX, p<0.05) in ZEB1 expression levels. In case of ABCB1 gene lack of influence on the mRNA level was observed (p>0.05). We also observed significant decrease of ZEB1 expression in MCF7 cells with 20 μM and 50 μM EGCG (p<0.05). In addition, EGCG (20 μM) caused an increase of MDM2 and PTEN mRNA levels in almost 100% (p<0.05) and 40% (p>0.05), respectively. Lack of the influence of EGCG was noted for the TWIST1 gene expression. In case of MCF7/DOX we showed an increase of mRNA level of PTEN gene about 50% (p<0.05). These results suggest that EGCG may be potentially used in adjuvant therapy in the breast cancer treatment.
EN
The aim of this study was to use a two-marker assay for the detection of breast can­cer cells circulating in patients' blood. We have applied a PCR-based methodology to follow up the possibility of the development of metastatic disease in stage I and II pa­tients who had undergone curative surgery. Since the number of circulating cancer cells in peripheral blood is very low, the technique for their detection needs to be not only highly sensitive, but also very specific. The reverse transcriptase-polymerase chain reaction (RT-PCR) technique may improve the sensitivity of breast cancer cell detection up to only a few cells per one million. The principle of the RT-PCR assay is to amplify a messenger RNA characteristic for breast epithelial cells in a blood sam­ple. Since we do not expect such cells to be circulating in peripheral blood of healthy subjects, detection of the characteristic mRNA should indicate the presence of circu­lating breast cancer cells. We analyzed the usefulness of three mRNA markers: cytokeratin 19 (CK19), mammaglobin (hMAM) and S subunit of human chorionic gonadotropin (S-hCG) for this test. Blood samples (112) were obtained from 55 patients, in stages I and II, with or without metastasis to regional lymph nodes (N0 or N1). We found that a two-marker assay increases the sensitivity of detection of breast cancer cells in com­parison with a single-marker one. Combination of two tumor-specific mRNA mark­ers, hMAM/CK19 or S-hCG/CK19, allowed the detection of circulating breast cancer cells in 65% of N1 patients and 38% of N0 patients. By comparison, the combination hMAM/-hCG allowed the detection of circulating breast cancer cells in the blood of 68% of N1 patients and 46% of N0 patients. Addition of the third marker did not significantly increase the detection sensitivity.
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2009
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tom 14
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nr 3
466-480
EN
Protein kinase B (PKB/Akt) is a serine-threonine kinase functioning downstream of phosphatidylinositol 3-kinase (PI-3 kinase) in response to mitogen or growth factor stimulation. In several cell types, it plays an important anti-apoptotic role. TPA is a potent regulator of the growth of many different cell types. Here, we detected that TPA could induce cell apoptosis in the gastric cancer cell line, BGC-823. We also found that TPA inhibited the expression of PKB/Akt in a TPA concentration- and time-dependent manner. Furthermore, TPA inhibited the phosphorylation of PKB at Ser473, but did not affect the phosphorylation of Thr308. It only attenuated the expression of PKB/Akt and the phosphorylation of Ser473 in the cell nucleus, whereas it did not change the PKB/Akt distribution in BGC-823 cells. These results suggest that PKB/Akt inhibition by TPA may be the important factor in the mechanism of effect of TPA on gastric cell lines.
EN
The primary physical and chemical parameters that define the hypopolarized plasma cell membrane of malignant (cancer) cells compared to non-malignant cells reflect universal characteristics. The median value for the resting membrane potential is the constant for the Nernst equation without reference to discrepancies in ion concentrations and is identical to Boltzmann energies at 37 °C. The threshold energy defining space-time converges with access to entropic processes that are reflected in the morphology of cancer cells and tumors. Slowing of growth in cancer cell lines but not normal cells following exposure to weak (~1 to 10 μT) patterned magnetic fields occurs when the energy induced within the cell corresponds to the energy equivalent of the hypopolarized membrane potential. The optimal temporal parameters for the efficacy of these fields can be derived from Hubble‟s parameter and the transform function for “noise” or “random” patterns within the system. Quantitative solutions and experimental data indicate that the cancer cell may be dominated by entropic process that can be attenuated or blocked by temporally-structured applied magnetic fields whose intensity matches the increment of energy associated with this threshold.
EN
The results of several experimental studies have shown that ascorbic acid inhibits tumor growth and metastasis. Ascorbic acid is an antioxidant that acts as a scavenger for a wide range of reactive oxygen species (ROS). Both tumour metastasis and cell migration have been correlated with the intracellular ROS level, so it was postulated that the inhibitory effect of ascorbic acid derivatives on cell motility may be caused by scavenging of ROS. Time-lapse analyses of Walker 256 carcinosarcoma cell migration showed that both the speed of movement and the cell displacement were inhibited by ascorbic acid applied in concentrations ranging from 10 to 250 μM. This effect correlated with a reduction in the intracellular ROS level in WC 256 cells, suggesting that ROS scavenging may be a mechanism responsible for the inhibition of WC 256 cell migration. However, another potent antioxidant, N-acetyl-L-cysteine, also efficiently decreased the intracellular ROS level in WC 256 cells, but did not affect the migration of the investigated cells. These results demonstrate that intact, unmodified ascorbic acid applied in physiologically relevant and nontoxicconcentrations exerts an inhibitory effect on the migration of WC 256 carcinosarcoma cells, and that this may be one of the factors responsible for the anti-metastatic activity of vitamin C. However, our data does not support the hypothesis that the scavenging of intracellular ROS is the main mechanism in the inhibition of cancer cell migration by ascorbic acid.
EN
hTERT (human telomerase reverse transcriptase) plays a key role in the process of cell immortalization. Overexpression of hTERT has been implicated in 85% of malignant tumors and offers a specific target for cancer therapy. In this paper, we describe an effective approach using a single-chain variable fragment (scFv) intrabody derived from monoclonal hybridoma directed against hTERT to attenuate the immortalization of human uterine cervix and hepatoma cells. The scFv we constructed had a high affinity to hTERT, and specifically neutralized over 70% of telomere synthesis activity, thereby inhibiting the viability and proliferation of the cancer cells. Our results indicate that this anti-hTERT intrabody is a promising tool to target hTERT and intervene in the immortalization process of cancer cells.
EN
In this work, using the two-dimensional finite difference time domain method, we are theoretically studying the optical properties of a two-dimensional photonic crystal biosensor based on silicon rods arranged as a square structure in an air bottom with two waveguides and a nanocavity. For this purpose, six different cells are infiltrated into the point defect. These six cells are Jurkat, HeLa, PC-12, MDA-MB-231, MCF-7, and basal cells. As a result, we have successfully detected cancer and benign cases of these cells through resonance peaks in the transmission spectrum. We evaluated the sensitivity, quality factor, detection limit, and figure of merit at different values for sensing region radius for optimization purposes. We report that we observed the maximum sensitivity of 1350 nm/RIU at 0.15 μm for the basal cell. Finally, the proposed biosensor can be a miniaturized structure with extreme sensitivity in cancer cell detection models.
EN
 Increased expression and activity of proteins driving cell cycle progression as well as inactivation of endogenous inhibitors of cyclin-dependent kinases (CDKs) enhance the proliferative potential of cells. Escape of cells during malignant transformation from the proper cell cycle control rendering them independent from growth factors provides rationale for therapeutic targeting of CDKs. Exposure of rapidly growing human MCF-7 breast cancer and HeLa cervix cancer cells to roscovitine (ROSC), a selective inhibitor of CDKs, inhibits their proliferation by induction of cell cycle arrest and/or apoptosis. The outcome strongly depends on the intrinsic traits of the tumor cells, on their cell cycle status prior to the onset of treatment and also on ROSC concentration. At lower dose ROSC primarily inhibits the cell cycle-related CDKs resulting in a strong cell cycle arrest. Interestingly, ROSC arrests asynchronously growing cells at the G2/M transition irrespective of the status of their restriction checkpoint. However, the exposure of cancer cells synchronized after serum starvation in the late G1 phase results in a transient G1 arrest only in cells displaying the intact G1/S checkpoint. At higher dosage ROSC triggers apoptosis. In HeLa cells inhibition of the activity of CDK7 and, in consequence, that of RNA polymerase II is a major event that facilitates the initiation of caspase-dependent apoptosis. In contrast, in the caspase-3-deficient MCF-7 breast cancer cells ROSC induces apoptosis by a p53-dependent pathway. HIPK2-mediated activation of the p53 transcription factor by phosphorylation at Ser46 results in upregulation of p53AIP1 protein. This protein after de novo synthesis and translocation into the mitochondria promotes depolarization of the mitochondrial membrane.
EN
The aim of the present study was to assess the possible correlation of p53 with CEA and Ca 19-9 serum levels as well as with selected clinicopathological data. 46 patients, who were gastrectomized due to gastric cancer between 1998 and 2001, were analyzed. The concentration of CEA and Ca 19.9 was estimated in serum. Mean percentage of p53-positive cells in present group was 33,69 %. The comparison of mean percentage of p53-positive cells with IHC reaction intensity revealed statistically significant, directly proportional correlation, with p<0,001. Mean CEA and Ca 19-9 serum concentration were 1,75± 1,71 ng/ml, and 17,34±44,73 U/ml respectively. No significant correlation between p53-expression, CEA and Cal9-9 was noted respecting several clinicopathological data of tumors. However clear trend of higher CEA and Cal9-9 values in groups of potentially worse prognosis (T3-T4; Nl-2; III grade of disease) was observed.
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