جستجوی مقالات مرتبط با کلیدواژه "colorectal cancer" در نشریات گروه "زیست شناسی"

Fusobacterium nucleatum (F. nucleatum) is an anaerobic, gram-negative bacterium, morphologically an elongated bacillus with a sharp end belonging to the Bacteroidaceae. It is the normal flora of the mouth that is present in other organs in some diseases. Given the role of F. nucleatum in the creation and development of human diseases, it is very important to investigate its characteristics and functions. However, due to the obligate anaerobic nature of F. nucleatum, purification and long-term storage of the bacteria pose problems. The aim of this study is to find an optimal method for the purification of F. nucleatum to enable a detailed study of the functions and mechanisms of the bacteria to provide new therapeutic approaches to control or treat the diseases caused by F. nucleatum for future studies.

Samples were taken from deep periodontal pockets of 16 patients using 40 size paper points with tryptic soy broth transfer medium (first method) and Columbia agar culture medium with gas pack type A and anaerobic jar (second method). The samples were then examined for the presence of F. nucleatum by macroscopic and microscopic observations, biochemical tests, PCR  and sequencing.

The results showed that the tryptic soy broth transfer medium was not able to preserve and keep the bacteria alive, and the purified F. nucleatum was isolated by direct transfer to  Columbia agar culture medium with gas pack type A and anaerobic jar.

Due to the obligate anaerobic nature of F. nucleatum, the use of transfer medium is not efficient for isolation due to the greater exposure of bacteria to air oxygen, and the optimal method for purification of F. nucleatum is the second sampling method.

The activity of Wnt signaling pathway is increased in colorectal cancer. For this reason, finding new positive and negative regulators for this pathway is a treatment and diagnostic strategy of colorectal cancer. Our bioinformatics analysis indicated that hsa-miR-424 (miR-424) could be a possible regulator of the Wnt signaling pathway. Accordingly, the expression level of miR-424 in colorectal cancer tissues was elevated compared with normal pairs and the results of RT-qPCR showed a significant increase in miR-424 expression (p < 0.01). Then, molecular analyzes using Top/Fop Flash and RT-qPCR techniques indicated that miR-424 overexpression leads to increased Wnt pathway activity in the SW480 cell line. In addition, the small molecules IWP-2 and PNU-74654 were used to inhibit the Wnt signaling pathway, and the miR-424 overexpression suggested that exert its effect on the level of β-catenin complex degradation. Then, dual-luciferase assay validated the interaction between miR-424 and APC. Overall, our results suggest miR-424 is a positive regulator of the Wnt signaling pathway, and it could be a possible prognosis for colorectal cancer.

Cancer is a global concern and colorectal cancer (CRC( accounts for the second most common cause of cancer related death in the world. Nanotechnology could enhance the effectiveness of chemotherapy as a common therapeutic approach through development of smart nanoparticles (NPs). In this context, theranostic nanoparticles with both imaging and therapeutic potentials are considered as promising platforms in diagnosis and treatment of advanced cancers.

Here, we designed and synthesized magnetic mesoporous silica nanoparticles (SPION-MSNs) in which release of 5-fluorouracil (5-FU) at physiological conditions was inhibited with pH-responsive gold gatekeepers. Heterofunctional polyethylene glycol (PEG) polymer was then conjugated onto the outer surface of nanoparticles and non-targeted nanoparticles were successfully synthesized. In order to achieve active and specific targeting, non-targeted nanoparticles were armed with an epithelial cell adhesion molecule (EpCAM) aptamer (Apt) for selective drug delivery of 5-FU to colorectal cancer cells. Finally, the physicochemical properties of NPs including functional groups, surface charge and their size were fully characterized with Fourier transform infrared (FTIR) spectra and dynamic light scattering (DLS) in each step. Moreover, morphology and homogeneity of SPION-MSNs were evaluated using field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM) and atomic force microscopy (AFM). The cumulative release of 5-FU from nanoparticles was compared in buffer solutions with two different pH values (pH 7.4 and 5.4). In the final step, anti-cancer potential and cytotoxicity of free 5-FU, non-targeted, and targeted nanoparticles were assessed on human colorectal adenocarcinoma HT-29 cells and Chinese hamster ovary cells.

Core-shell NPs, SPION-MSNs, were successfully prepared and the FTIR spectra showed specific peaks at the surface of nanoparticles. Obtained results from DLS measurements showed that the synthesized formulation had negative charges with size of 20 nm. Moreover, the morphology of SPION-MSNs indicated spherical shape with uniform distribution. After introducing amine groups, the surface charge was shift to positive and the two bands at 2965 and 1,560 cm−1 in the FT-IR spectrum were appeared and assigned to CH2-CH2 and N-H groups, respectively. The results indicated, 5-FU was encapsulated in the open pores of MSNs and the encapsulation efficiency (EE%) and drug loading capacity (LC%) were about 98% and 49%, respectively. The release of 5-FU from NPs showed pH-dependent manner, with an initial rapid release (within 6 h) followed by a sustained release for 96 h at pH 5.4. interestingly, the cumulative release of 5-FU was about 3.9% in neutral medium over 96 h. the results supported the Intelligent release of cargoes from theranostic nanoparticles. At the final step, targeted nanoparticles were successfully synthesized with a final size diameter of 78 nm and negative surface charge. In vitro results demonstrated higher cytotoxicity and anti-cancer property of targeted nanoparticles against EpCAM-positive HT-29 cells as compared to the EpCAM-negative CHO cells, confirming the effectiveness of aptamer as a targeting ligand.

These findings suggest that application of the targeted formulation can be considered as a promising theranostic platform for EpCAM-positive CRC cells. However, further experiments are required before it can be practiced in the clinic.

This study aimed to compare the expression levels of LncRNA CRNDE in malignant colorectal tumorsand adjacent normal tissues of patients by Real Time-PCR.

20 pairs of colorectal tumors and adjacent normal tissue specimens were prepared from the tumor bank of Imam Khomeini Hospital in Tehran University of Medical Sciences. After total RNA extraction from cancerous and normal tissues, cDNA was synthesized, and the expression levels of LncRNA CRNDE were examined using the Real Time-PCR method. A one-way analysis of variance (ANOVA) and Tukey's HSD test used for statistical analysis of results.

The results showed a two-fold increase in LncRNA CRNDE expression in all 20 colorectal cancer samples compared with the normal cells.

According to the significant increase of the LncRNA CRNDE expression in cancer cells relative to normal cells and its presence in the bloodstream, this LncRNA maybe used as a non-invasive diagnostic biomarker for early detection of colorectal cancer.

Colorectal cancer is one of the most common cancers. Epigenetic change has been considered by many scientists as a therapeutic target. Hyper acetylation of chromatin components by sodium butyrate can alter gene regulation. This study aims to investigate the effects of sodium butyrate on Bax and Bcl-2 gene expression.

Caco-2 cell line was treated with different concentrations of sodium butyrate (25 mM to 150 mM) based on IC50 concentration in two time periods of 24 hours and 48 hours. Bax and Bcl-2 gene expression were measured by qReal-Time PCR technique and Bcl2/Bax ratio was evaluated.

The results showed that sodium butyrate increased the expression of Bax gene and decreased the expression of Bcl-2 gene in treated cells compared to the control group, which was statistically significant (p < /em> <0.05), and 25 mM was selected as the most effective dose after 48 hours of treatment. Also, the Bcl-2/Bax ratio at the same concentration showed a significant decrease

Sodium butyrate induces apoptosis in cancer cells by reducing the expression ratio of Bcl-2/Bax. It can be used as a therapeutic target but needs further investigation.

In the past decades, nanotechnology has received much attention in order to develop new drug delivery systems to overcome the limitations of routine drugs in the treatment of diseases. Nanotechnology offers very useful applications in the diagnosis and treatment of cancer, as nanomaterials can penetrate into body tissues at the cellular and molecular levels.

In the present study, samarium nanoparticles were synthesized by the extract of ginger using green chemistry synthesis method. The size of the synthesized nanoparticles was investigated by dynamic light scattering (DLS) technique and formation of new functional groups was investigated by FT_IR technique. The morphology of the nanoparticles was determined using FE-SEM scanning electron microscopy. Finally, the cytotoxicity and anticancer activity of samarium nanoparticles were studied against human colorectal cancer cell line of HCT116 after 24 and 48 hours incubation times using tetrazolium colorimetric assay (MTT assay).

Dynamic light scattering data in agreement with Fe-SEM data revealed the formation of globular nanoparticles of 60 nm. Cell survival assay showed Ic50 values (the concentration of the compound that induces 50% death in cancer cells) of 90 (equal to 23.1 mg/ml) and 81 μM (equal to 20.7 mg/ml) of samarium nanoparticles on HCT116 cell line after 24 and 48 hours incubation times, respectively.

It is concluded that the newly green synthesized samarium nanoparticles with anticancer activity might be a good candidate for colon cancer therapy.

The bowel or colorectal cancer (CRC) is one of the most common fatal malignancies caused by environmental and genetic factors. The phenomenal growth in the number of people with CRC worldwide, especially in Iran highlights the importance of research on CRC.The current study focused on molecular pathways involved in the carcinogenesis of colorectal cancer to identify a new diagnostic and therapeutic biomarker for CRC.Colorectal cancer is the consequence of dysplasia in the initial intestinal appendages also known as polyps which are different and unknown in terms of morphology, molecular mechanisms, and the ability to affect intestinal carcinogenesis. In this cross-sectional study, 208 colorectal tissue biopsy specimens, including 34 tumor tissue, , 60 precancerous lesions with  adjacent tissue, as well as 20 normal tissue specimens were collected. CUL3 gene expression was evaluated using real-time PCR method. No significant difference was observed in mRNA expression level of CUL3 between polyp tissues and their normal adjacent samples (p = 0.35).Our results showed a statistically significant difference in CUL3 expression neither between tumor tissues and their adjacent normal samples (p = 0.89) nor among tumor and polyp groups (p = 0.48).CUL3 could play a critical role in regulating carcinogenesis and progression of CRC through stimulating proteasomal degradation of various tumor suppressors or oncogenes. Studies on CUL3-affected substrates in colorectal cancer are of significant importance.