Evaluation of the tumor-targeting specific imaging and killing effect of a CEA-targeting nanoparticle in colorectal cancer.

INTRODUCTION: Colorectal cancer (CRC) is a prevalent digestive malignancy with significant global mortality and morbidity rates. Improving diagnostic capabilities for CRC and investigating novel therapeutic approaches are pressing clinical imperatives. Additionally, carcinoembryonic antigen (CEA) has emerged as a highly promising candidate for both colorectal tumor imaging and treatment. METHODS: A novel active CEA-targeting nanoparticle, CEA(Ab)-MSNs-ICG-Pt, was designed and synthesized, which served as a tumor-specific fluorescence agent to help in CRC near-infrared (NIR) fluorescence imaging. In cell studies, CEA(Ab)-MSNs-ICG-Pt exhibited specific targeting to RKO cells through specific antibody-antigen binding of CEA, resulting in distribution both within and around these cells. The tumor-targeting-specific imaging capabilities of the nanoparticle were determined through in vivo fluorescence imaging experiments. Furthermore, the efficacy of the nanoparticle in delivering chemotherapeutics and its killing effect were evaluated both in vitro and in vivo. RESULTS: The CEA(Ab)-MSNs-ICG-Pt nanoparticle, designed as a novel targeting agent for carcinoembryonic antigen (CEA), exhibited dual functionality as a targeting fluorescent agent. This CEA-targeting nanoparticle showed exceptional efficacy in eradicating CRC cells in comparison to individual treatment modalities. Furthermore, it exhibits exceptional biosafety and biocompatibility properties. CEA(Ab)-MSNs-ICG-Pt exhibits significant promise due to its ability to selectively target tumors through NIR fluorescence imaging and effectively eradicate CRC cells with minimal adverse effects in both laboratory and in vivo environments. CONCLUSION: The favorable characteristics of CEA(Ab)-MSNs-ICG-Pt offer opportunities for its application in chemotherapeutic interventions, tumor-specific NIR fluorescence imaging, and fluorescence-guided surgical procedures.

Prognostic and predictive value of tumor deposits in advanced signet ring cell colorectal cancer: SEER database analysis and multicenter validation.

BACKGROUND: Colorectal signet-ring cell carcinoma (SRCC) is a rare cancer with a bleak prognosis. The relationship between its clinicopathological features and survival remains incompletely elucidated. Tumor deposits (TD) have been utilized to guide the N staging in the 8th edition of American Joint Committee on Cancer (AJCC) staging manual, but their prognostic significance remains to be established in colorectal SRCC. PATIENTS AND METHODS: The subjects of this study were patients with stage III/IV colorectal SRCC who underwent surgical treatment. The research comprised two cohorts: a training cohort and a validation cohort. The training cohort consisted of 631 qualified patients from the SEER database, while the validation cohort included 135 eligible patients from four independent hospitals in China. The study assessed the impact of TD on Cancer-Specific Survival (CSS) and Overall Survival (OS) using Kaplan-Meier survival curves and Cox regression models. Additionally, a prognostic nomogram model was constructed for further evaluation. RESULTS: In both cohorts, TD-positive patients were typically in the stage IV and exhibited the presence of perineural invasion (PNI) (P < 0.05). Compared to the TD-negative group, the TD-positive group showed significantly poorer CSS (the training cohort: HR, 1.87; 95% CI, 1.52-2.31; the validation cohort: HR, 2.43; 95% CI, 1.55-3.81; all P values < 0.001). This association was significant in stage III but not in stage IV. In the multivariate model, after adjusting for covariates, TD maintained an independent prognostic value (P < 0.05). A nomogram model including TD, N stage, T stage, TNM stage, CEA, and chemotherapy was constructed. Through internal and external validation, the model demonstrated good calibration and accuracy. Further survival curve analysis based on individual scores from the model showed good discrimination. CONCLUSION: TD positivity is an independent factor of poor prognosis in colorectal SRCC patients, and it is more effective to predict the prognosis of colorectal SRCC by building a model with TD and other clinically related variables.

Twist2 promotes self-renewal of liver cancer stem-like cells by regulating CD24.

Twist2 is a highly conserved basic helix-loop-helix transcription factor that plays a critical role in embryogenesis. Recent evidence has revealed that aberrant Twist2 expression contributes to tumor progression; however, the role of Twist2 in human hepatocellular carcinoma (HCC) and its underlying mechanisms remain undefined. In this report, we demonstrate that Twist2 is overexpressed in human HCC tumors. We show that ectopic expression of Twist2 induces epithelial-mesenchymal transition phenotypes, augments cell migration and invasion and colony-forming abilities in human HCC cells in vitro, and promotes tumor growth in vivo. Moreover, we found a higher percentage of CD24(+) liver cancer stem-like cells in Twist2-transduced HCC cells. Twist2-expressing cells exhibited an increased expression of stem cell markers Bmi-1, Sox2, CD24 and Nanog and an increased capacity for self-renewal. Knockdown of CD24 in HepG2/Twist2 cells decreased the levels of Sox2, pSTAT3 and Nanog, and reversed the cancer stem-like cell phenotypes induced by ectopic expression of Twist2. Furthermore, Twist2 regulated the CD24 expression by directly binding to the E-box region in CD24 promoter. Therefore, our data demonstrated that Twist2 augments liver cancer stem-like cell self-renewal in a CD24-dependent manner. Twist2-CD24-STAT3-Nanog pathway may play a critical role in regulating liver cancer stem-like cell self-renewal. The identification of the Twist2-CD24 signaling pathway provides a potential therapeutic approach to target cancer stem cells in HCCs.

[The clinical significance of preoperative enteral immune nutrition in patients with malignant gastrointestinal tumors].

OBJECTIVE: To study the impact of preoperative enteral immune nutrition on patients with malignant gastrointestinal tumors. METHODS: 82 patients with malignant gastrointestinal tumors were divided equally into 2 groups:enteral nutrition group (EN) and normal diet group (Control). Enteral Nutritional Emulsion (TPF-T) served as nasogastically-fed liquid diet for the patients in EN group over a period of 7 days prior to surgery. Normal diet was given to the patients in control group under the same condition as those in EN group in terms of calories and nitrogen contents. Enzyme linked immunosorbent assay (ELISA) was performed to determine the quantity of serum albumin (ALB), transferrin protein (TRF), pre-albumin (PA) and retinol binding protein (RBP). Flow cytometry (FCM) was performed to determine T cell subsets. Postoperative complications, resumption of peristalsis, length of hospital stay, and nutritional costs were also recorded. RESULTS: TRF, PA and RBP increased significantly in the patients in EN group compared with those in control group (P < 0.05). The patients in EN group had significantly higher proportions of CD3+, CD4+/CD8+ higher than those of control (P < 0.05). No serious complications (eg. death or gastrointestinal fistula) were found in the patients. The total nutritional cost for the patients in EN group was similar to that of the controls (P > 0.05). The patients in EN group had less postoperative complications, quicker resumption of peristalsis, shorter hospital stay and lower level of postoperative nutrition cost compared with those of controls (P < 0.05). CONCLUSION: Enteral nutrition support can improve the nutritional status and immunity of patients with malignant gastrointestinal tumors, which has both pre-operative and post-operative benefits for the patients.

[Cytosine deaminase and thymidine kinase double suicide gene system driven by carcinoembryonic antigen promoter for the treatment of colorectal carcinoma xenograft in nude mice].

OBJECTIVE: To explore the therapeutic efficacy of double suicide gene system driven by carcinoembryonic antigen (CEA) promoter (Cp-CDglyTK) on colorectal carcinoma xenograft in nude mice. METHODS: The plasmid pcDNA3.1(-)Cp-CDglyTK was transfected into the CEA-positive SW480 and CEA-negative HeLa cells respectively. The expression of suicide gene was detected by RT-PCR. And the transfected cells were treated with 5-fluorocytosine (5-FC) and ganciclovir (GCV) at different concentrations and the cell-killing and bystander effects assayed by methyl thiazolyl tetrazolium (MTT). By a transplantation of cultivated cells, SW480 or HeLa cell lines were injected subcutaneously into right axillary of nude mice to establish 96 SW480 and 72 HeLa tumor animal models. Nude mice were completely randomized with statistical software according to tumor volume. For prodrug therapy, 48 SW480-bearing mice were divided equally into 4 groups of I-IV. At the same time, 48 HeLa-bearing mice were divided equally into 4 groups of V-VIII. Groups I & V received an intratumoral injection of PBS, groups II & VIGCV and 5-FC intratumorally, groups III & VII PBS intraperitoneally and groups IV & VIII GCV and 5-FC intraperitoneally. Forty-eight SW480-bearing mice were divided equally into 4 groups of IX∼XII and 24 Hela-bearing ones into groups of & in therapy experiment by suicide gene plus prodrug. Six groups received an intratumoral injection of liposome Lipofectamine and plasmid CP-CDglyTK and then an intraperitoneal injection of drug. The groups of IX and received an injection of PBS, group X GCV, group XI 5-FC and groups XII & GCV and 5-FC. The observation parameters included tumor bulk, tumor weight, survival time and treatment effect in each group. RESULTS: SW480 cells transfected by plasmid pcDNA3.1(-)Cp- CDglyTK expressed CDglyTK gene. The inhibition rates of GCV and 5-FC were significantly higher than those of HeLa cells (59.87% ± 0.21% vs 9.90% ± 0.09%, P < 0.01). And higher inhibition rates and stronger bystander effect existed in double versus single produg (all P < 0.05). Tumor size, final tumor weight and survival time of nude mice in groups ofII, IV, VI & VIII had no significant difference with groups ofI, III, V & VII (all P < 0.05). Final tumor size and weight of group XII was significantly smaller than those of groups of IX, X and XI ((150.0 ± 3.2) vs (522.5 ± 1.9) and (256.8 ± 10.4) and (260.7 ± 2.2) mm(3), (54.1 ± 10.4) vs (682.0 ± 12.0) and (251.8 ± 15.1) and (271.6 ± 17.7) mg, all P < 0.05). Meanwhile, the tumor inhibition rate and survival time of group XII(92.1% and (25.7 ± 0.8)d) were significant higher and longer than group X (63.1% and (21.8 ± 0.5) d) and group XI (60.2% and (18.0 ± 0.9) d) (all P < 0.05). However, no significant difference existed in tumor size, final tumor weight and survival time between groups and (all P > 0.05). The inhibition rate of group was merely 0.9%. CONCLUSION: CDglyTK double suicide gene system driven by CEA promoter may inhibit CEA positive colorectal cancer xenograft in prodrug-treated nude mice.

A novel active mitochondrion-selective fluorescent probe for the NIR fluorescence imaging and targeted photodynamic therapy of gastric cancer.

The annual morbidity and mortality due to gastric cancer are still high across the world, posing a serious threat to public health. Improving the diagnosis rate of gastric cancer and exploring new treatments are urgent issues in the clinical field. In recent years, photosensitizer (PS)-based photodynamic therapy (PDT) has proven to be an effective cancer treatment strategy and can be used to treat a variety of cancers. Developing PSs with tumor-targeting ability and high singlet oxygen yield (Φ(1O2)) is the key to improving the PDT effect. Herein, we developed a novel diagnosis and treatment system (Cy1395-NPs). Our active thio-photosensitizer is based on the sulfur substitution strategy as it can reduce the S1-T1 energy gap, which can promote the process of intersystem crossing (ISC), thus resulting in high ROS generation efficiency. Cy1395-NPs exhibited stable spectral characteristics, satisfactory biocompatibility and high 1O2 yield under laser irradiation due to the introduction of the sulfur atom. In cellular studies, Cy1395-NPs could specifically target MKN45 cells via integrin αvß3-mediated cRGD endocytosis and selectively aggregate in the mitochondria. Cy1395-NPs had no obvious cytotoxicity for MKN45 cells and exerted obvious phototoxicity due to the production of 1O2 under laser irradiation. The in vivo results showed that the fluorescence signal from the tumor site was obviously enhanced in 16-48 h, and Cy1395-NPs could selectively target solid tumors with a retention time of about 32 h. Under laser irradiation, Cy1395-NPs significantly inhibited tumor growth and led to significant tumor suppression and apoptosis. In summary, the developed Cy1395-NPs could actively target tumors and exert mitochondrial selectivity, showing an excellent fluorescence imaging effect. Under the irradiation of an 808 nm laser, Cy1395-NPs achieved good inhibition of gastric cancer cells both in vitro and in vivo, thus displaying the functions of tumor targeting, mitochondrial selectivity, fluorescence imaging and tumor inhibition. Our strategy provides a new diagnostic and treatment method for gastric cancers in clinical settings.

Histidine-rich calcium binding protein promotes gastric cancer cell proliferation, migration, invasion and epithelial-mesenchymal transition through Raf/MEK/ERK signaling.

Histidine-rich calcium binding protein (HRC) is a new type of Ca2+ homeostasis regulator, which acts as a nonnegligible role in regulating intracellular calcium homeostasis. Here, we demonstrated that HRC expression was upregulated in human gastric cancer (GC) samples, and its expression level was closely correlated with the overall survival (OS) rate of GC patients and the malignant potential of GC cell lines. Knockdown of HRC inhibited migration, invasion, and proliferation of GC cell lines in vitro, while HRC overexpression promoted GC cell migration, invasion, and proliferation in vitro, as well as the growth of subcutaneous tumors and peritoneal tumors in vivo. In terms of the mechanism, knockdown of HRC reduced the intracellular calcium ion level and the CaM protein level. Through cell function experiments, we found that HRC regulated the Raf/MEK/ERK pathway through Ca2+/CaM signaling and ultimately affected the epithelial­mesenchyme transition (EMT) of GC. In summary, we revealed that HRC represents a potential target for GC treatment.

miR-27b inhibits gastric cancer metastasis by targeting NR2F2.

Increasing attention is focused on the down-regulation of miRNAs in cancer process. Nuclear receptor subfamily 2 (NR2F2, also known as COUP-TFII) is involved in the development of many types of cancers, but its role in gastric cancer remains elusive. In this experiment, oncomine and Kaplan-meier database revealed that NR2F2 was up-regulated in gastric cancer and that the high NR2F2 expression contributed to poor survival. MicroRNA-27b was targeted and down-regulated by NR2F2 in human gastric cancer tissues and cells. The ectopic expression of miR-27b inhibited gastric cancer cell proliferation and tumor growth in vitro and in vivo. Assays suggested that the overexpression of miR-27b could promote MGC-803 cells' migration and invasion and retard their metastasis to the liver. In addition, down-regulation of miR-27b enhanced GES-1 cells' proliferation and metastasis in vitro. These findings reveal that miR-27b is a tumor suppressor in gastric cancer and a biomarker for improving patients' survival.

Reduced tumorigenicity and drug resistance through the downregulation of octamer-binding protein 4 and Nanog transcriptional factor expression in human breast stem cells.

Breast cancer is the most common type of malignancy among females. Previous studies examining breast cancer tissue have demonstrated the presence of stem cells, and have detected octamer­binding protein 4 (Oct4) and Nanog transcription factor expression. In the present study, breast cancer stem cells (CSCs) were isolated and enriched from MDA­MB­231 breast cancer cell lines, and were defined as MDA­MB­231 stem cells using flow cytometry. The expression of Oct4 and Nanog in breast CSCs were detected by quantitative polymerase chain reaction and western blotting. RNA interference (RNAi) was used in order to downregulate the expression of Oct4 and Nanog. Drug resistance and tumor­initiating capability following in vivo injection of MDA­MB­231 stem cells trans-duced with negative RNAi, Oct4 RNAi and Nanog RNAi were compared with that of MDA­MB­231 stem cells without siRNA transfection as a control group. In addition the capability of MDA­MB­231 breast cancer cells to initiate tumor formation in mice was compared with that of MDA­MB­231 stem cells. A paclitaxel inhibition test was also conducted in order to detect resistance of MDA­MB­231 breast cancer stem cells to this treatment. The MDA­MB­231 stem cells were revealed to exhibit elevated percentages of the cluster of differentiation (CD)44+CD24­/low subset, high tumorigenicity and resistance to chemotherapy, all of which are characteristic stem cell properties. In addition, the MDA­MB­231 stem cells were more tumorigenic in vivo. Furthermore, the breast CSCs also expressed high levels of the Oct4 and Nanog transcription factors. Therefore, downregulation of Oct4 or Nanog expression may reduce chemotherapeutic drug resistance and tumorigenicity in breast CSCs. In conclusion, Oct4 and Nanog expression may be a key factor in the development of resistance to chemotherapy and tumor growth of breast CSCs. This finding indicates that Oct4 or Nanog­targeted therapy may be a promising means of overcoming resistance to chemotherapy and inhibiting tumor growth in breast cancer treatment.

Simvastatin inhibits inflammation in ischemia-reperfusion injury.

Ischemia/reperfusion (I/R) is associated with leukocyte accumulation and tissue injury. The aim of this research was to investigate the protective effect of simvastatin on hind limb I/R inflammation and tissue damage. Mice were subjected to hind limb ischemic insult for 2 h and were simultaneously administered an intraperitoneal injection of simvastatin (5 mg/kg); this was followed by 36 h of reperfusion. Myeloperoxidase (MPO) levels in the muscles of the hind limb were determined. CXC chemokines and pro-inflammatory cytokines, such as macrophage inflammatory protein (MIP)-2, cytokine-induced neutrophil chemoattractant (KC), interleukin (IL)-6, tumor necrosis factor (TNF)-α, and P-selectin, were assessed using enzyme-linked immunosorbent assay (ELISA). Leukocyte rolling and adhesion in vitro was assessed to indicate leukocyte recruitment at the site of inflammation. Quantitative measurement of skeletal muscle tissue injury was performed. The fluorescent dye level in tissue and serum was used to determine hind limb vascular leakage and tissue edema after I/R. Systemic and differentiated leukocytes were also counted. Simvastatin significantly reduced MIP-2, KC, TNF-α, MPO, IL-6, and P-selectin levels compared to the sham group and I/R plus pretreatment with phosphate-buffered saline (PBS) group (P<0.05). Compared to the sham group and I/R plus PBS group, the I/R plus simvastatin group had attenuated inflammation, vascular leakage, and muscular damage (P<0.05). Simvastatin also significantly inhibited leukocyte rolling and adhesion compared to PBS (P<0.05). Our results suggest that simvastatin may be an effective protectant against tissue injury associated with I/R.