A Novel Approach for Treating Lipomas: Percutaneous Microwave Ablation Combined with Liposuction.

Lipomas, benign adipose tissue tumors, are a common occurrence but currently, the options for their treatment are limited, with surgical excision being the most frequently used management pathway. This scenario can often lead to unsatisfactory cosmetic results and significant patient discomfort. This paper introduces a novel technique, percutaneous microwave ablation with liposuction, to address these challenges. The innovative procedure aims to enhance patient satisfaction, minimize post-operative discomfort, and improve aesthetic outcomes. The technique involves two key steps: (1) the application of percutaneous microwave ablation to selectively disrupt the lipoma cells, followed by (2) a targeted liposuction procedure to remove the ablated lipoma tissue. Our approach optimizes the removal of the lipoma and preserves the surrounding healthy tissue, reducing the risk of local recurrence and improving the cosmetic result. The use of preoperative ultrasound imaging allows for precise localization and delineation of the lipoma, aiding in the planning and execution of the procedure. This novel approach to lipoma treatment is reliable, associated with minimal morbidity, and consistently yields effective results. Additionally, it provides a new perspective on lipoma management, potentially changing the paradigm of current treatment approaches.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of endoscopic thyroidectomy via the oral vestibule approach and the areola approach for papillary thyroid carcinoma.

BACKGROUND: The endoscopic thyroidectomy areola approach (ETAA) has been widely applied for papillary thyroid carcinoma (PTC), but leaves scars and is not truly minimally invasive. The oral vestibular approach (ETOVA) leaves no scars and is even more minimally invasive. However, there have been few comparative studies of ETAA and ETOVA for PTC. The purpose of our research was to compare two PTC treatment methods in terms of feasibility, safety, efficacy, and cosmetic results. METHODS: A total of 129 patients with PTC underwent thyroidectomy combined with central lymph node dissection by the same surgeon. Among them, 79 patients underwent the ETOVA, and the others underwent the ETAA. We compared the two groups in terms of operative outcomes, postoperative complications, and cosmetic results. RESULTS: No significant differences were found in the clinical characteristics between the ETOVA and ETAA groups. There were no significant differences in the number of removed lymph nodes (P = 0.279) or the number of positive lymph nodes (P = 0.569), but the ETOVA group had a higher number of removed lymph nodes. There was also no significant difference in blood loss volume(P = 0.180), postoperative drainage volume (P = 0.063), length of hospital stay (P = 0.182), transient RLN injury rate (P = 1.000), permanent RLN injury rate (P = 1.000), or recurrence rate (P = 1.000). The ETOVA was a longer operation than the ETAA was (P < 0.01). The ETOVA group had less pain (VAS 1: P < 0.01, VAS 3: P = 0.001), less neck discomfort (1 month after surgery: P = 0.009, 3 months after surgery: P = 0.033), and better cosmetic results (P = 0.001). CONCLUSIONS: The ETOVA is not inferior to the ETAA in terms of safety and curability of PTC and is advantageous in terms of central lymph node dissection, minimal invasiveness, and cosmetic results. TRIAL REGISTRATION: This study was approved by the Ethics Committee of Zhongshan Hospital of Xiamen University (2017 V1.0). No funding was received.

Application of carbon nanoparticles in endoscopic thyroid cancer surgery: a systematic review and meta-analysis.

Background: There has been a substantial increase in incidence of thyroid cancer globally over the past three decades, emphasizing the necessity for efficient surgical management. Surgical intervention requires meticulous lymphatic dissection; however, it is challenging to both accurately identify lymph nodes and preserve the surrounding structures. We investigated the role of carbon nanoparticles in endoscopic thyroid cancer surgery to improve surgical effects and reduce postoperative complications. Methods: Chinese and English literature databases from inception to May 2023 were searched based on inclusion criteria, and data were extracted independently by two investigators. STATA software was used for data analysis. Results: A comprehensive systematic review and meta-analysis were conducted with 13 publications (9 randomized and 4 non-randomized controlled trials). The results demonstrated that the application of carbon nanoparticles in thyroid surgery led to an increase in the number of retrieved lymph nodes and identification of metastatic lymph nodes. Furthermore, it considerably reduced the rate of improper parathyroidectomy and the incidence of postoperative hypocalcemia. Conclusion: The application of carbon nanoparticles can effectively improve the effects of surgical treatment, can enhance the identification of intraoperative lymph nodes, reduce postoperative complications, and protect the integrity and function of the parathyroid gland. Systematic Review Registration: www.crd.york.ac.uk/PROSPERO, identifier, CRD42023420504.

Analysis of gastrointestinal function and prognostic value of tumor markers in patients with laparoscopic radical resection of colorectal cancer.

OBJECTIVE: To analyze the gastrointestinal function and prognostic value of tumor markers (TMs) in patients with laparoscopic radical resection of colorectal cancer (LRRCC). METHODS: The research population of this retrospective study comprised 141 patients with CC who received treatment in the Zhongshan Hospital of Xiamen University between July 2017 and August 2018, including 74 cases (observation group, OG) treated with LRRCC and 67 cases (control group, CG) undergoing open surgery (OS). Postoperative gastrointestinal function and complications were recorded. Besides, alterations in serum TMs carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), and the 3-years survival of patients were observed. Receiver operating characteristic (ROC) curves were used to determine the prognostic value of TMs. Risk factors affecting the prognosis of LRRCC patients were analyzed by the Cox regression model. RESULTS: Significantly higher levels of motilin (MOT) and gastrin (GT) were determined in OG compared with CG. The two groups showed no notable difference in the postoperative complication rate. Postoperative serum CEA and CA199 levels were obviously lower in OG as compared with CG. A higher 3-year survival rate was determined in OG. The areas under the receiver operating characteristic (ROC) curve (AUCs) of CEA and CA19-9 levels in predicting patients' 3-year survival were 0.826 and 0.867, respectively. According to the Cox regression analysis, tumor diameter, lymph node involvement, TNM staging, vascular invasion, CEA, and CA19-9 were independent risk factors for poor prognosis of LRRCC patients. CONCLUSIONS: LRRCC is well-tolerated by patients with CC and contributes to favorable outcomes. Besides, CEA and CA19-9, the two TMs, may be candidate prognostic markers for patients undergoing LRRCC.

Network Pharmacology Analysis of Huangqi Jianzhong Tang Targets in Gastric Cancer.

Background: The Chinese medicine, Huangqi Jianzhong Tang (HJT), is widely used to treat gastric cancer (GC). In this study, network pharmacological methods were used to analyze the potential therapeutic targets and pharmacological mechanisms of HJT in GC. Methods: Bioactive components and targets of HJT and GC-related targets were identified using public databases. The protein-protein interaction network of potential targets of HJT in GC was constructed using the Cytoscape plug-in (v3.8.0), CytoHubba. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, in addition to molecular docking and animal experiments to verify the results of network pharmacology analysis. Results: A total of 538 GC-related targets were identified. The bioactive components of HJT were selected for drug-likeness evaluation and binomial statistical model screening, which revealed 63 bioactive components and 72 targets. Based on GO enrichment analysis, all targets in the protein-protein interaction network were mainly involved in the response to oxidative stress and neuronal death. Further, KEGG enrichment analysis suggested that the treatment of GC with HJT mainly involved the Wnt signaling pathway, PI3K-Akt signaling pathway, TGF-ß signaling pathway, and MAPK signaling pathway, thereby providing insights into the mechanism of the effects of HJT on GC. Conclusion: This study revealed the potential bioactive components and molecular mechanisms of HJT, which may be useful for the treatment of GC, and provided insights into the development of new drugs for GC.

Quantitative study of preoperative staging of gastric cancer using intravoxel incoherent motion diffusion-weighted imaging as a potential clinical index.

PURPOSE: To determine the utility of intravoxel incoherent motion (IVIM) diffusion-weighted imaging in quantitative analysis of preoperative tumor (T) and node (N) stages of gastric cancer, and to quantify the diagnostic threshold of IVIM parameters for serosal invasion and lymphatic metastasis. MATERIALS AND METHODS: From October 2016 to February 2020, 98 patients with gastric cancer who were receiving treatment in Zhongshan Hospital, China, were subject to an IVIM sequence imaging analysis. The IVIM sequence data were imported into software for post-processing of tumor regions of interest, and the IVIM parameters (the microvascular volume fraction (f), the molecular diffusion coefficient (D) and perfusion-related incoherent microcirculation (D*) were calculated. The variation of these IVIM parameters with different tumor-node metastasis (TNM) stages were analyzed by one-way analysis of variance. The IVIM parameters of serosal invasion and lymphatic metastasis were examined by receiver operating characteristic curve analysis and t-tests. RESULTS: A total of 98 gastric cancer patients (65 males and 33 females) with an average age of 61.9 years were enrolled in this study. There were 14 patients in stage T1, 14 in stage T2, 10 in stage T3 and 60 in stage T4a+b. There were 37 patients in stage N0, 19 in stage N1, 18 in stage N2 and 24 in stage N3. Statistically significant associations were found between the D values and T stages of gastric cancer. The D values of stage T4 cancers were significantly different from those of stage T2, T3 and T4 cancers. The D value decreased with increasing T stage. The mean D values of stages were 1.432 × 10-3 mm2/s (T1), 1.225 × 10-3 mm2/s (T2), 1.154 × 10-3 mm2/s (T3) and 0.9468 × 10-3 mm2/s (T4). The extent of the invasion of serosa was found to be significantly correlated with D value, with the diagnostic threshold for D being 1.107 × 10-3 mm2/s. In addition, different pathological N stages of gastric cancer lesions showed statistically significantly variations in f values, but no correlation was found with different N stages. Finally, the extent of lymphatic metastasis was found to be correlated with D values, with the diagnostic threshold being 1.1739 × 10-3 mm2/s. There was no statistically significant correlation between the IVIM MRI parameters and tumor size. The grade of tumor was found to be significantly correlated with D* value, with the diagnostic threshold for D* being 1.516 × 10-2 mm2/s. There was no statistically significant correlation between the ADC value and tumor size. There was a significant difference in the ADC values among different T and N stage cancers. ADC value had statistically significant to distinguish gastric cancer with or without serosal invasion, its detection efficiency was not as high as that of D value, with an AUC of 0.628 and 0.830, respectively. The ADC value was not statistically significant in distinguishing gastric cancer with or without lymphatic metastasis (P ≥ 0.05). The ADC value had not statistically significant in distinguishing gastric cancer between low and medium-high grade (P ≥ 0.05). CONCLUSION: We found that significant differences existed between whole-volume IVIM parameters of different T or N stages in gastric cancers, and were able to quantify different T or N stages of gastric cancer by the values of these parameters. The results of this quantitative study provide new tools for evaluating the prognosis of gastric cancer and will be valuable for the development of an new imaging method for determining the morphological stages of gastric cancer.

Inhibition of circRNA circVPS33B Reduces Warburg Effect and Tumor Growth Through Regulating the miR-873-5p/HNRNPK Axis in Infiltrative Gastric Cancer.

BACKGROUND: Circular RNA VPS33B (circVPS33B) has been revealed to be upregulated in gastric cancer (GC) tissues. However, the role of circVPS33B in infiltrative GC is indistinct. METHODS: Expression of circVPS33B was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration, and invasion of infiltrative GC cells (XGC-1) were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT), plate clone, wound-healing, or transwell assays. Protein levels were detected by Western blotting. Measurements of extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were executed using an XF96 extracellular flux analyzer. Glucose uptake and lactate production were analyzed by glycolysis assay. The regulatory mechanism of circVPS33B had been explored by bioinformatics analysis, dual-luciferase reporter assay, and/or RNA pull-down assay. In vivo tumorigenesis assay was executed to verify the oncogenicity of circVPS33B. RESULTS: CircVPS33B was upregulated in infiltrative GC tissues and cells. CircVPS33B silencing decreased tumor growth in vivo and inhibited proliferation, migration, invasion, EMT, and Warburg effect of infiltrative GC cells in vitro. Mechanically, circVPS33B regulated heterogeneous nuclear ribonucleoprotein K (HNRNPK) expression via sponging miR-873-5p. Furthermore, miR-873-5p inhibitor offset circVPS33B knockdown-mediated effects on malignant behaviors and Warburg effect of infiltrative GC cells. HNRNPK overexpression reversed the inhibitory impact of miR-873-5p mimic on malignant behaviors and Warburg effect of infiltrative GC cells. CONCLUSION: CircVPS33B accelerated Warburg effect and tumor growth through regulating the miR-873-5p/HNRNPK axis in infiltrative GC, manifesting that circVPS33B might be a potential target for infiltrative GC treatment.

Circular RNA circHECTD1 prevents Diosbulbin-B-sensitivity via miR-137/PBX3 axis in gastric cancer.

BACKGROUNDS: Gastric cancer (GC) is general disease in human digestive system with malignancy. Emerging findings indicated that hsa_circ_0031452 (circHECTD1) was strictly associated with carcinogenesis. Nevertheless, the role of circHECTD1 in drug-resistance still needed to be explained. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to examine the expression profiles of circHECTD1, microRNA (miR)-137, and pre-leukemia transcription factor 3 (PBX3). The function of circHECTD1 in tumorigenesis was evaluated via xenograft tumor model. The IC50 of Diosbulbin-B (DB) was detected using Cell Counting Kit-8 (CCK8). Cell-cycle and apoptosis were reckoned by flow cytometry. Besides, western blot was administrated to reckon the levels of PBX3 and cell apoptotic indicators. Moreover, the interrelation between miR-137 and circHECTD1 or PBX3 was expounded by dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull down assays. RESULTS: We uncovered that circHECTD1 was ectopically up-regulated in GC tissues and cells. CircHECTD1 deficiency sensitized DB-treatment in DB-evoked AGS and HGC-27 cells. In vivo assay, circHECTD1 silencing led to the tumor reduction. Also, circHECTD1 served as miR-137 sponge in a sequence-complementary manner. Furthermore, transfection of miR-137 inhibitor markedly eliminated circHECTD1 absence-mediated promotion of DB-sensitivity in GC cells. Moreover, PBX3, a target of miR-137, play a DB-resistant role in GC cells. Fascinatingly, the deletion of PBX3 reversed the impact of miR-137 repression and circHECTD1 knockdown on DB-sensitivity in vitro. CONCLUSIONS: CircHECTD1 served as an oncogene by a novel miR-137/PBX3 axis, which might supply an underlying biomarker for the diagnosis and prognosis of GC management.

Effect of PI3K/Akt Signaling Pathway on PRAS40Thr246 Phosphorylation in Gastric Cancer Cells.

BACKGROUND: We aimed to investigate the effect of PI3K/Akt signaling pathway on PRAS40Thr246 phosphorylation in gastric cancer cells. METHODS: The study was conducted from April 2017 to January 2018 in Zhongshan Hospital, Xiamen University, Xiamen, China. Gastric cancer cells were divided into three groups: gastric cancer cell group, LY294002 group and MK-2206 group. Specific tests were conducted accordingly. RESULTS: Inhibition of PI3K/Akt signaling pathway activation and PRAS40Thr246 phosphorylation could inhibit proliferation and invasion and promote apoptosis of gastric cancer cells, and PRAS40Thr246 phosphorylation could activate PI3K/Akt signaling pathway. CONCLUSION: The levels of PI3K/Akt signaling pathway related proteins and p-PRAS40Thr246 were significantly increased in gastric cancer cells. p-PRAS40-Thr246 was able to reflect the activation of the PI3K/Akt signaling pathway, reflecting the sensitivity of the PI3K/AKT signaling pathway to inhibitors.

p21-activated protein kinase 1 induces the invasion of gastric cancer cells through c-Jun NH2-terminal kinase-mediated activation of matrix metalloproteinase-2.

Gastric cancer (GC) is one of the most common malignancies worldwide. The prognosis of GC is poor, mostly due to widespread metastasis. p21-activated kinase 1 (Pak1), the best characterized member of an evolutionarily conserved family of serine/threonine kinases, plays an important role in the regulation of cell morphogenesis, motility, mitosis and angiogenesis. By qRT-PCR and Gelatin zymograph assay, we demonstrated in the present study that stable overexpression of Pak1 induced matrix metalloproteinase (MMP)-2 mRNA expression and activity in the human MKN45 GC cell line. Conversely, knockdown of endogenous Pak1 expression by small interfering RNA (siRNA) decreased MMP-2 mRNA expression and activity in the MKN45 GC cells. Activation of c-Jun N-terminal kinase (JNK) was required for Pak1-induced upregulation of MMP-2 mRNA level and activity. Moreover, upregulation of MMP-2 by Pak1 via the JNK pathway notably promoted the invasion of MKN45 GC cells. Overexpression of MMP-2 mRNA was once again confirmed to be associated with GC metastasis. In conclusion, our results demonstrated for the first time that Pak1 stimulated MMP-2 mRNA expression and activity in MKN45 GC cells. The JNK signaling pathway was involved in Pak1 modulation of MMP-2, which was important for MKN45 GC cell invasiveness.

Prognostic role of phospho-PRAS40 (Thr246) expression in gastric cancer.

INTRODUCTIONS: Phospho-PRAS40(Thr246) (phosphorylated proline-rich Akt substrate of 40 kilodaltons at Thr246) is a biomarker for phosphatidylinositol 3-kinase (PI3K) pathway activation and AKT inhibitors sensitivity. MATERIAL AND METHODS: In this study, we immunohistochemically investigated the expression of phospho-PRAS40(Thr246) in 141 gastric cancer tumors, and evaluated its clinicopathological and prognostic significance. RESULTS: Sixty-four cases (45.4%) were defined as phospho-PRAS40(Thr246) positive. Phospho-PRAS40(Thr246) correlated positively with lymph node metastasis, lymphatic infiltration, vascular infiltration and shorter survival. Furthermore, phospho-PRAS40(Thr246) is an independent prognostic factor for gastric cancer. CONCLUSIONS: Our data suggest that phospho-PRAS40(Thr246) was frequently expressed in gastric cancers, and correlated with malignant progression and poor prognosis of patients. PI3K pathway-targeted therapies should be considered in the future treatment of gastric cancers.

Clinical significance of combined testing of YKL-40 with CEA in Chinese colorectal cancer patients.

BACKGROUND: To investigate the practical value of individual and combined testing of plasma levels of YKL-40, CEA, and CA199 for auxiliary diagnosis and detection of recurrence of colorectal cancer. METHODS: ELISA and ECLIA were used to evaluate levels of YKL-40, CEA, and CA199 in 120 colorectal cancer patients (56 initial-diagnosis, 42 post-operative, and 22 recurrent cases). Forty-three patients with benign colorectal disease and 36 healthy patients were enrolled as controls. The relationship between YKL-40 and clinical indicators of tumor pathology was analyzed. The positive rate and diagnostic efficacy of single and combined YKL-40, CEA, and CA199 testing were assessed in patients with colorectal cancer. RESULTS: Plasma YKL-40 in the cancer group was significantly higher than in the benign control and healthy control group, and the mean values were 145.4 ng/mL, 107.7 ng/mL, and 51.3 ng/mL (p < 0.05), respectively. With 72 ng/mL as the diagnostic threshold, the sensitivity and specificity of YKL-40 in colorectal cancer diagnosis were found to be 73.2% and 66.7%, respectively. Early-stage colorectal cancer patients showed a YKL-40 positive rate (73%) significantly higher than those of CEA and CA199 (50% and 32%, respectively; p < 0.05). When YKL-40 testing was combined with CEA or CA199, the positive rate increased to 82.1% and 80.3%, respectively. Through ROC curve analysis of the post-operative recurrent group against the non-recurrent group, the areas under the curve for YKL-40, CEA, and CA199 were found to be 0.907, 0.714, and 0.759, respectively. Based on the Dukes classification, the mean YKL-40 value for stages A/B, C, and D were 120.1 ng/mL, 131.7 ng/mL, and 226.8 ng/mL (p = 0.008), respectively. The plasma YKL-40 level gradually increased as the disease progressed. Lower degrees of tumor differentiation were correlated with higher YKL-40 levels. The mean YKL-40 values of high, medium, and low tumor differentiation groups were 96.8 ng/mL, 127.5 ng/mL, and 225.7 ng/mL (p = 0.004), respectively. CONCLUSIONS: The benefits of using YKL-40 testing are higher than CEA and CA199 for the monitoring of colorectal cancer recurrence. Combined testing of both YKL-40 and CEA was found to be optimal for auxiliary diagnosis of colorectal cancer. Plasma YKL-40 was found to be suitable for auxiliary diagnosis of colorectal cancer.

A study on the extraction process of active ingredients from Akebia Stem and an analysis of their anti-gastric cancer activity.

The study investigated the extraction process of active ingredients from akebia stem and an analysis of their anti-gastric cancer activity. Three different extraction methods were used to obtain extracts, namely the decoction method (group A), reflux extraction method (group B), and maceration method (group C), of which reflux extraction method and maceration method used ethanol as the extraction solvent, while decoction method used distilled water for extraction. The differences in anti-gastric cancer activity of the three extracts were compared. MTT assay was used to test and compare the inhibitory effects of extracts obtained in A, B, and C groups on gastric cancer cells. The results showed that the dry extract obtained by heat reflux extraction with "water-ethanol" ratio of 1:2, extractant volume of 70 ml, with ethanol as extraction solvent presented the best inhibitory activity on gastric cancer SGC-7901 cells in this study. Its inhibitory effect did not change over time, and was directly proportional to the concentration.

P21-activated protein kinase 1 is overexpressed in gastric cancer and induces cancer metastasis.

P21-activated protein kinase (Pak1), a main downstream effector of small Rho GTPases, plays an important role in the regulation of cell morphogenesis, motility, mitosis and angiogenesis. However, the role of Pak1 in gastric cancer metastasis remains unclear. Here, we showed that Pak1 is overexpressed in gastric cancer tissues from 74 patients by immunohistochemistry. Overexpression of Pak1 was associated with metastasis and prognosis of gastric cancer. In addition, overexpression of Pak1 increased gastric cancer cell motility and invasion, whereas downregulation of Pak1 expression reduced gastric cancer cell migration and invasion. In further study, data showed that activated Pak1 inhibited stress fiber and focal adhesion complex formation in gastric cancer cells and led to the formation of motile phenotypes. Importantly, activated Pak1 elicited phosphorylation of the ERK and JNK-dependent pathway in gastric cancer cell lines. In conclusion, our results suggest that Pak1 is overexpressed in gastric cancer and plays an important role in the metastasis of gastric cancer. The mechanism by which Pak1 induces cancer metastasis may involve activation of ERK and JNK.

Alterations of tumor-related genes do not exactly match the histopathological grade in gastric adenocarcinomas.

AIM: To investigate the diverse characteristics of different pathological gradings of gastric adenocarcinoma (GA) using tumor-related genes. METHODS: GA tissues in different pathological gradings and normal tissues were subjected to tissue arrays. Expressions of 15 major tumor-related genes were detected by RNA in situ hybridization along with 3' terminal digoxin-labeled anti-sense single stranded oligonucleotide and locked nucleic acid modifying probe within the tissue array. The data obtained were processed by support vector machines by four different feature selection methods to discover the respective critical gene/gene subsets contributing to the GA activities of different pathological gradings. RESULTS: In comparison of poorly differentiated GA with normal tissues, tumor-related gene TP53 plays a key role, although other six tumor-related genes could also achieve the Area Under Curve (AUC) of the receiver operating characteristic independently by more than 80%. Comparing the well differentiated GA with normal tissues, we found that 11 tumor-related genes could independently obtain the AUC by more than 80%, but only the gene subsets, TP53, RB and PTEN, play a key role. Only the gene subsets, Bcl10, UVRAG, APC, Beclin1, NM23, PTEN and RB could distinguish between the poorly differentiated and well differentiated GA. None of a single gene could obtain a valid distinction. CONCLUSION: Different from the traditional point of view, the well differentiated cancer tissues have more alterations of important tumor-related genes than the poorly differentiated cancer tissues.

[A preliminary study on construction of targeting double suicide gene therapy vector pcDNA3.1 (-) Cp-CD-TK].

OBJECTIVE: To construct the targeting double suicide gene therapy vector pcDNA3.1 (-) Cp-CD-TK driven by carcino-embryonic antigen promoter (CEA promoter, Cp), and to investigate whether the vector could control the expression of CD-TK gene specificity and impact on proliferation of CEA positive colon cancer cells. METHODS: Three kinds of target gene, Cp, CD, and TK were obtained by PCR, the products were double digested and inserted into pcDNA3.1 (-), then the targeting vector pcDNA3.1 (-) Cp-CD-TK was transfected into CEA positive human colon cancer SW480 cells and CEA negative Hela cells, the expression of CD-TK was examined by RT-PCR. The sensitivities of SW480 cells transfected with pcDNA3.1 (-) Cp-CD-TK to pro-drug 5-Fluorocytosine (5-Fc) and Ganciclovir (GCV) were detected by MTT analysis. RESULTS: Recombinants with Cp, CD and TK insert were obtained. Constructed targeting gene therapy vector pcDNA3.1 (-) Cp-CD-TK was confirmed by gel electrophoresis and sequencing. RT-PCR analysis further confirmed CD-TK gene was expressed in SW480 cells and was not expressed in CEA negative Hela cells. MTT assay demonstrated that SW480 cells transfected with targeting vector pcDNA3.1 (-) Cp-CD-TK were sensitive to pro-drug 5-Fc and GCV. CONCLUSION: Targeting double suicide gene therapy vector pcDNA3.1 (-) Cp-CD-TK was constructed correctly. The vector could make CD-TK gene express specifically in CEA positive cells for the purpose of targeting killing colon cancer.

[Anti-tumor and bystander effects of cationic liposome-mediated CD/5-FC suicide gene system combined with interferon-gamma in vivo].

OBJECTIVE: To study the antitumor and distant bystander effects of cationic liposome-mediated cytosine deaminase (CD)/5-fluorocytosine (5-FC) suicide gene system combined with interferon-gamma (IFN-gamma) in vivo. METHODS: Murine hepatoma 22 (H22) cells transfected by CD gene were inoculated subcutaneous in Kunming mice in the left axillary region, and the H22 cells without CD gene transfection were inoculated in the right axillary region. The mice were randomly divided into 4 groups and treated with normal saline , 5-FC, IFN-gamma, and 5-FC+ IFN-gamma on a daily basis. The tumor inhibition and distant bystander effects were observed in the mice. RESULTS: Exposure of CD gene-transfected tumor to 5-Fc resulted in obvious tumor growth inhibition with an inhibition rate of 78.38%, which was significantly increased to 93.21% (P<0.01) with 5-Fc +IFN-gamma treatment. A notable distant bystander effect in the CD/5-FC suicide gene system was observed in vivo, with a tumor inhibition rate of was 54.42%; when combined with IFN-gamma, the inhibition rate increased significantly to 87.57% (P<0.05). CONCLUSION: When combined with IFN-gamma, CD/5-FC suicide system has stronger anti-tumor and distant bystander effects. CD/5-FC suicide gene system combined with IFN-gamma may provide a potential therapy for malignant tumors.