[Overexpression of miR-21 promotes proliferation and reduces apoptosis in non-small cell lung cancer].

OBJECTIVE: To elucidate the regulatory mechanism underlying proliferation and anti-apoptosis in NSCLC by overexpression of miR-21. METHODS: Real-time PCR was used to measure miR-21 abundance in non-small cell lung cancer (NSCLC) tumor samples and adjacent normal tissues, as well as NSCLC cell lines. Tumor suppressor genes as potential targets of miR-21 were predicted by sequence analysis. Luciferase assay and Western blot were used to assess the regulatory effect. The effect on A549 cell viability and apoptosis by miR-21-induced gene repression was tested by trypan-blue exclusion and flow cytometry. RESULTS: miR-21 expression was 2.24-fold higher in the NSCLC tumor samples and 3.06-fold higher in the A549 cells than that in the adjacent normal tissues. Sequence prediction and gene expression regulation assays showed that miR-21 could reversely regulate the expression of PDCD4 (P < 0.01). Suppression of miR-21 expression is associated with an elevation of Pdcd4, resulting in a significant reduction of proliferation and the apoptosis rate (2.6%) was increased to 10.9%. Moreover, the anti-proliferation and pro-apoptotic effect by miR-21 suppression could be reversed by PDCD4 knock down. CONCLUSION: Suppression of the tumor suppressor PDCD4 expression may be one of the important regulatory pathways of the miR-21-mediated cell proliferation and decrease of apoptosis in non-small cell lung cancer.

Chitosan nanoparticle as gene therapy vector via gastrointestinal mucosa administration: results of an in vitro and in vivo study.

This study was designed to investigate the in vitro and in vivo transfection efficiency of chitosan nanoparticles used as vectors for gene therapy. Three types of chitosan nanoparticles [quaternized chitosan -60% trimethylated chitosan oligomer (TMCO-60%), C(43-45 KDa, 87%), and C(230 KDa, 90%)] were used to encapsulate plasmid DNA (pDNA) encoding green fluorescent protein (GFP) using the complex coacervation technique. The morphology, optimal chitosan-pDNA binding ratio and conditions for maximal in vitro transfection were studied. The in vivo transfection was conducted by feeding the chitosan/pDNA nanoparticles to 12 BALB/C-nu/nu nude mice. Both conventional and TMCO-60% could form stable nanoparticles with pDNA. The in vitro study showed the transfection efficiency to be in the following descending order: TMCO-60%>C(43-45 KDa, 87%)>C(230 KDa, 90%). TMCO-60% proved to be the most efficient and the optimal chitosan/pDNA ratio being 3.2:1. In vivo study showed most prominent GPF expression in the gastric and upper intestinal mucosa. GFP expression in the mucosa of the stomach and duodenum, jejunum, ileum, and large intestine were found, respectively, in 100%, 88.9%, 77.8% and 66.7% of the nude mice examined. TMCO-60%/pDNA nanoparticles had better in vitro and in vivo transfection activity than the other two, and with minimal toxicity, which made it a desirable non-viral vector for gene therapy via oral administration.

[In-vivo targeted imaging of hepatocellular carcinoma in nude mice using quantum dot probes].

OBJECTIVE: To explore in-vivo targeted imaging techniques for liver cancer detection using quantum dots (QDs) labeled probes in a nude mouse model of human hepatocellular carcinoma. METHODS: Mercaptoacetic acid (MAA) modified QDs were linked to mouse-anti-human alpha-fetoprotein (AFP) monoclonal antibody to form water soluble QD-AFP-Ab probes, which were validated by spectra analyses and transmission electron microscope. The probes were firstly used to detect AFP antigen in human hepatocellular carcinoma cell line HCCLM6 in-vitro by one-step immunofluorescence method. In-vivo tumor xenografts and lung metastases models were then established by inoculation of HCCLM6 cells subcutaneously and into the tail vein of nude mice, respectively. QD-AFP-Ab probes were injected into the tail vein of the tumor bearing mice for live animal fluorescence imaging. Spectra of tumor and normal tissue were analyzed under illumination of Ti: sapphire laser. Serum levels of alanine amino transferase, aspartate amino transferase, blood urea nitrogen and creatinine were determined by conventional biochemical analysis. The liver, spleen, lungs, kidneys, heart and brain of the experimental nude mice were investigated for nonspecific uptake of the probes by confocal microscope. RESULTS: The QD-AFP-Ab probes had broad excitation spectra and high fluorescence intensity. They could specifically and efficiently recognize AFP antigen in hepatocellular carcinoma cells. Tumor targeting imaging using these probes were successful without any acute toxicity to the experimental animals. Spectra analysis showed that the probes per field were lower in the centre than the periphery of the tumor. Non-specific uptake of QD-AFP-Ab probes occurred mainly in the liver, spleen and lungs. CONCLUSIONS: QD-AFP-Ab probes have good optical properties and biocompatibility for in-vivo targeted imaging of hepatocellular carcinoma. Such approach promises to be highly desirable for molecular targeted research of liver cancer.

Effects of perioperative cimetidine administration on peripheral blood lymphocytes and tumor infiltrating lymphocytes in patients with gastrointestinal cancer: results of a randomized controlled clinical trial.

BACKGROUND/AIMS: Cimetidine (CIM) seems to have positive effects on the immune systems of cancer patients. This study was conducted to investigate the effects of perioperative administration of CIM on the peripheral blood lymphocytes, natural killer (NK) cells and tumor infiltrating lymphocytes (TIL) in patients with gastrointestinal (GI) cancer. METHODOLOGY: Forty-nine GI cancer patients were randomized into a treatment group which took CIM in the perioperative period, and a control group which did not take the drug. The treatment was initiated 7 days (d) before operation and continued until 10 d after surgery. At baseline examination, before operation, on the 2nd and the 10th postoperative d, peripheral blood T lymphocytes, helper T cells, T suppressor cells, and NK cells were measured by immunocytochemical method. The surgical specimens were examined for TIL response, and immunohistochemical study was performed to measure the proportion of T and B lymphocytes in the TIL population. RESULTS: In comparison with normal controls, both the treatment and the control groups had decreased T cells, helper T cells and NK cells at baseline. In the control group, total T cells, helper T cells and NK cells declined progressively with the disease course and the decreases became more profound after operation. From the baseline to the 2nd postoperative d, the proportion of total T cells, helper T cells, and NK cells went down from 60.5+/-4.6 to 56.2+/-3.8 percent, from 33.4+/-3.7 to 28.1+/-3.4 percent, and from 15.0+/-2.8 to 14.2+/-2.2 percent, respectively. On the other hand, there were significant improvements in these parameters after CIM treatment. On the 10th postoperative d, the treatment group had significantly higher percentages of total T cells, helper T cells and NK cells than control group. Moreover, CIM treatment also boosted the TIL response, as was reflected by findings that 68% (17/25) of the patients in the treatment group had significant TIL responses and only 25% (6/24) of the cases had discernible TIL response. CONCLUSIONS: Perioperative application of CIM to GI cancer patients could help restore the diminished cellular immunity boost TIL responses to tumor.

TGF beta1 expression and angiogenesis in colorectal cancer tissue.

AIM: Transforming growth factor TGF beta1 is involved in a variety of important cellular functions,including cell growth and differentiation, angiogenesis, immune function and extracellular matrix formation. However, the role of TGF beta(1) as an angiogenic factor in colorectal cancer is still unclear. We investigate the relationship between transforming growth factor beta(1) and angiogenesis by analyzing the expression of transforming growth factor TGF beta(1) in colorectal cancer, as well as its association with VEGF and MVD. METHODS: The expression of TGF beta(1),VEGF, as well as MVD were detected in 98 colorectal cancer by immunohistochemical staining. The relationship between the TGF beta(1) expression and VEGF expression,MVD was evaluated. To evaluate the effect of TGF beta(1) on the angiogenesis of colorectal cancers. RESULTS: Among 98 cases of colorectal cancer,37 were positive for TGF beta(1) 37.8% 36 for VEGF 36.7% respectively. The microvessel counts ranged from 19 to 139.8, with a mean of 48.7(standard deviation,21.8). The expression of TGF beta(1) was correlated significantly with the depth of invasion, stage of disease, lymph node metastasis, VEGF expression and MVD. Patients in T3-T4, stage III-IV and with lymph node metastasis had much higher expression of TGF beta(1) than patients in T1-T2, stage I-II and without lymph node metastasis (P<0.05). The positive expression rate of VEGF(58.3%) in the TGF-beta(1) positive group is higher than that in the TGF-beta(1) negative group(41.7%, P<0.05). Also, the microvessel count (54+/-18) in TGF-beta(1) positive group is significantly higher than that in TGF-beta(1) negative group(46+/-15, P<0.05). The microvessel count in tumors with both TGF-beta(1) and VEGF positive were the highest (58+/-20 36-140, P<0.05). Whereas that in tumors with both TGF-beta(1) and VEGF negative were the lowest (38+/-16, 19-60, P<0.05). CONCLUSION: TGF beta(1) might be associated with tumor progression by modulating the angiogenesis in colorectal cancer and TGF beta(1) may be used as a possible biomarker.

Cyclooxygenase-2 expression and angiogenesis in colorectal cancer.

AIM: Cyclooxygenase-2 is involved in a variety of important cellular functions, including cell growth and differentiation, cancer cell motility and invasion, angiogenesis and immune function. However, the role of cyclooxygenase-2 as an angiogenic factor in colorectal cancer tissue is still unclear. We investigated the relationship between cyclooxygenase-2 and angiogenesis by analyzing the expression of cyclooxygenase-2 in colorectal cancer tissue, as well as its association with vascular endothelial growth factor (VEGF) and microvascular density (MVD). METHODS: The expression of cyclooxygenase-2, VEGF, as well as MVD was detected in 128 cases of colorectal cancer by immunohistochemical staining. The relationship between the cyclooxygenase-2 and VEGF expression and MVD was evaluated. Our objective was to determine the effect of cyclooxygenase-2 on the angiogenesis of colorectal cancer tissue. RESULTS: Among 128 cases of colorectal cancer, 87 were positive for cyclooxygenase-2 (67.9 %), and 49 for VEGF (38.3 %), respectively. The microvessel counts ranged from 23 to 142, with a mean of 51.7 (standard deviation, 19.8). The expression of cyclooxygenase-2 was correlated significantly with the depth of invasion, stage of disease, metastasis (lymph node and liver), VEGF expression and MVD. Patients in T3-T4, stage III-IV and with metastasis had much higher expression of cyclooxygenase-2 than patients in T1-T2, stage I-II and without metastasis (P<0.05). The positive expression rate of VEGF (81.6 %) in the cyclooxygenase-2 positive group was higher than that in the cyclooxygenase-2 negative group (18.4 %, P<0.05). Also, the microvessel count (56+/-16) in cyclooxygenase-2 positive group was significantly higher than that in cyclooxygenase-2 negative group (43+/-12, P<0.05). The microvessel count in tumors with positive cyclooxygenase-2 and VEGF was the highest (60+/-18, 41-142, P<0.05), whereas that in tumors with negative cyclooxygenase-2 and VEGF was the lowest (39+/-16, 23-68, P<0.05). CONCLUSION: Cyclooxygenase-2 may be associated with tumor progression by madulating the angiogenesis in colorectal cancer tissue and used as a possible biomarker.

Transforming growth factor-beta1 in invasion and metastasis in colorectal cancer.

AIM: To investigate the role of TGFbeta1 in invasion and metastasis in colorectal cancer by analysing TGFbeta1 correlated with depth of tumor invasion, stage and metastasis. METHODS: Serum TGFbeta1 levels were determined in 50 patients with colorectal cancer and 30 healthy volunteers using a TGFbeta1 enzyme-linked immunosorbent assay. TGFbeta1 expression in primary and lymph node metastatic lesions were detected in 98 cases of colorectal cancer by immunohistochemical staining and in situ hybridization. RESULTS: Serum levels of TGFbeta1 in patients with colorectal cancer(40+/-18 microg.L(-1)) were significantly higher than those in the healthy control group(19+/-8 microg.L(-1)), P<0.05. Elevated levels of serum TGFbeta1 were found in 60 % of patients with colorectal cancer when the mean +2 s was used as the upper limit of the normal range (35.1 microg.L(-1)). Increases in serum TGFbeta1 levels were significantly associated with Duke's stage (P<0.05), but there was no significant difference between Duke's stage B patients and Duke's stage C patients. In the cytoplasm of cancer cells, TGFbeta1 was immunostained in 37.8 % (37/98) of colorectal cancer, and this expression was confirmed by in situ hybridization. Among 35 cases of colorectal cancer with lymph node metastatic lesions, TGFbeta1 positive staining was found in 18 (51.4 %) cases of primary tumor, and 25 (71.4 %) cases with lymph node metastatic lesions, respectively. Of 17 cases w ith no staining in the primary lesion, 7 (41.2%) casesshowed TGFbeta1 staining in the metastatic lesion. Serum TGFbeta1 levels and TGFbeta1 expression in colorectal cancer tissues were correlated significantly with depth of tumor invasion, stage and metastasis. Patients in stage C-D,T3-T4 and with metastasis had significantly higher TGFbeta1 levels than patients in stage A-B,T1-T2 and without metastasis (P<0.05). CONCLUSION: These results suggest that transforming growth factor-beta1 is closely related to the invasion and metastasis of colorectal cancer. It increased the invasive and metastatic potential of tumor by altering a tumor microenvironment. TGFbeta1 may be used as a possible biomarker.

Perioperative cimetidine administration promotes peripheral blood lymphocytes and tumor infiltrating lymphocytes in patients with gastrointestinal cancer: Results of a randomized controlled clinical trial.

AIM: To study the effects of perioperative administration of cimetidine (CIM) on peripheral blood lymphocytes, natural killer (NK) cells and tumor infiltrating lymphocytes (TIL) in patients with gastrointestinal (GI) cancer. METHODS: Forty-nine GI cancer patients were randomized into treatment group, who took CIM in perioperative period, and control group, who did not take the drug. The treatment was initiated 7 days before operation and continued for 10 days after surgery. At baseline examination before operation, on the 2nd and 10th postoperative days, total T lymphocytes, T helper cells, T suppressor cells, and NK cells in peripheral blood were measured respectively by immunocytochemical method using mouse-anti human CD(3), CD(4), CD(8) and CD(57) monoclonal antibodies. Blood samples from 20 healthy volunteers were treated in the same way as normal controls. Surgical specimens were examined during routine histopathological evaluation for the presence of TIL in tumor margin. Immunohistochemical study was performed to measure the proportion of T and B lymphocytes in TIL population. T and B lymphocytes were detected respectively using mouse-anti-human CD(3) and CD(20) monoclonal antibodies. RESULTS: In comparison with normal controls, both the treatment and control groups had decreased T cells, T helper cells and NK cells at baseline. In control group, total T cells, T helper cells and NK cells declined continuously with the disease progression and the decrease became more obvious after operation. From baseline to the 2nd postoperative day, the proportion of total T cells, T helper cells, and NK cells went down from 60.5+/-4.6% to 56.2+/-3.8%, 33.4+/-3.7% to 28.1+/-3.4%, and 15.0+/-2.8% to 14.2+/-2.2%, respectively. On the other hand, there were significant improvements in these parameters after CIM treatment. On the 10th postoperative day, the treatment group had significantly higher percentages of total T cells, T helper cells and NK cells than control group. Moreover, CIM treatment also boosted TIL response, as was reflected by findings that 68% (17/25) of the patients in treatment group had significant TIL responses and only 25% (6/24) of the cases had discernible TIL responses (P<0.01). CONCLUSION: Perioperative application of CIM to GI cancer patients could help restore the diminished cellular immunity induced by tumor burden and surgical maneuver. The drug could also boost TIL responses to tumor. These effects suggest that the drug be used as an immunomodulator for GI cancer patients.

[Quantum dots and their applications in cancer research].

Quantum dots are semiconductor nanocrystals with physical dimensions smaller than the exciton Bohr radius. As their fluorescence emissions are size-tunable, we can acquire any spectrum from ultraviolet (UV) to near-infrared by changing the particles' radiuses. The large Stokes shifts of quantum dots can be used to further improve detection sensitivity. The luminescence intensity is high and stable. Single quantum dots have longer excited state lifetimes, and they appear 10-20 times brighter than organic fluorescent dyes. And they have good biocompatibility because quantum dots with appropriate shells don't interfere with physiological processes, such as growth, development, signaling and motility. With the development of optical labeling and imaging technology, many present conventional biomedical methods have limitations in microcosmic direct real-time researches of bio-molecular interactions and early diagnosis of malignant tumors. The invention of quantum dots and their biomedical applications make them as good markers for tumor cell tracing and targeting in cancer research, such as prostate cancer, mammary cancer, cervical cancer, basal cell carcinoma, liver cancer, and melanoma. The current research is focused on tumor markers imaging and molecular interaction based on tangible carriers such as cells and tissues. The next research orientation would be to tap the potential of this highly sensitive technology to image tumor biomarkers in serum and other body fluids, so as to increase the early diagnosis rate of malignant tumors.

Study on the causes of local recurrence of rectal cancer after curative resection:analysis of 213 cases.

AIM:To study the local recurrent rate and the causes of rectal cancer after surgery.METHODS:The clinicopathological data of 213 rectal cancer patients and the follow-up information were analyzed. The overall recurrent rate and the recurrent rates from different surgical appreaches were calculated. The main causes of recurrence were investigated.RESULTS:Among the 213 cases, 73 (34.27%) had local recurrence. The recurrent time ranged from 3 months to 62 months after the first operation. Most of the recurrence (65/73, 89.04%) occurred within 3 years after operation.CONCLUSION:Local recurrence had no significant correlation with surgical methods or pathological types, but closely related to Dukes' stages, location of primary tumors and the length of the distal rectum resected. Early resection and a wide tumor free resection margin are key factors to prevent local recurrence.

[Expression and clinical significance of IGF-II mRNA and bcl-2 protein in colorectal adenocarcinomas].

BACKGROUND & OBJECTIVE: Insulin-like growth factor II (IGF-II) can stimulate cell proliferation; B cell lymphoma 2 (bcl-2) protein can strongly inhabit cell apoptosis. Recently, the overexpression of IGF-II and bcl-2 in colorectal cancer has been found, but the combined detection of them has not been reported. The objective of this study was to investigate the relationship between the expression of IGF-II, bcl-2 and the invasion, metastases of colorectal adenocarcinomas and to analyze the clinical significance of combined detection of these factors. METHODS: Forty-eight paraffin embedded samples from colorectal adenocarcinomas were selected. IGF-II mRNA was detected by using in situ hybridization. The expression of bcl-2 and PCNA protein were determined immunohistochemically, and TUNEL technique was used to detect apoptosis. Ten normal colorectal tissues were used as controls. The positive cell ratio of cancers was calculated by computer. The specimens with positive cell ratio < or = 30% were defined as negative. RESULTS: The expressions of IGF-II mRNA and bcl-2 protein were significantly higher in colorectal adenocarcinomas (38.70% +/- 7.80% and 30.97% +/- 7.40%) than in normal colorectal tissues(23.12% +/- 4.07% and 12.69% +/- 1.31%) (P < 0.01) and were related to Dukes' stage and lymph node metastases but were not associated with patient's age, gender, tumor site, tumor size and tumor differentiation. A negative correlation was observed between IGF-II mRNA and bcl-2 protein (P < 0.05). A positive correlation between IGF-II mRNA and PCNA, apoptosis as well as a negative correlation between bcl-2 and apoptosis were observed (P < 0.01). There was no correlation between bcl-2 and PCNA (P > 0.05). The patients with IGF-II mRNA (+) and bcl-2 (-) were regarded as the worst prognosis. CONCLUSION: The overexpression of IGF-II and bcl-2 in colorectal adenocarcinomas play an important role in the pathogenesis, progression, invasion, and metastases of the tumor. Determination of both IGF-II and bcl-2 expression would be helpful for decision making of adjuvant therapy.

[Clinical significance of detecting lymph node micrometastasis of colorectal cancer by reverse transcriptase-polymerase chain reaction (RT-PCR)].

BACKGROUND & OBJECTIVE: It remains controversial whether lymph node micrometastasis has impact on staging and prognosis of colorectal cancer. This study was to compare the sensitivity of reverse transcriptase- polymerase chain reaction (RT-PCR) in detecting lymph node micrometastasis of colorectal cancer with pathological morphology and immunohistochemistry, and assess the impact of lymph node micrometastasis on clinical staging and prognosis of colorectal cancer. METHODS: Lymph nodes from 56 cases of colorectal cancer radical resection specimens were studied by RT-PCR to detect the expression of cytokeratin 20 (CK20) mRNA, and compared with routine pathology detection using hematoxylin and eosine (HE) staining, and immunohistochemistry using monoclonal antibody specifically against CK20. The patients had been followed up for 5 years. RESULTS: A total of 432 lymph nodes in 56 patients were analysed by pathological morphology, immunohistochemistry, and RT-PCR, the detected positive lymph node numbers were 247 (57.2%), 269 (62.3%), and 316 (73.1%), respectively. The difference in metastatic lymph node numbers was significant between pathological morphology and RT-PCR method (P< 0.05). Five-year disease- free survival rates of PN0,PN1, and PN2 stages detected by RT-PCR method were 100%, 61.9%, and 55.6%, respectively, significantly higher than those obtained by pathological morphology method, which were 80.0%, 60.0%, and 50.0%, respectively (P< 0.05). CONCLUSIONS: Detecting lymph node micrometastasis of colorectal cancer with RT-PCR method is more sensitive than pathological morphology. RT-PCR method could define the TNM stage and make accurate prognosis for patients with colorectal cancer.