m6A-modified circFNDC3B inhibits colorectal cancer stemness and metastasis via RNF41-dependent ASB6 degradation.

Colorectal cancer (CRC) is the third most frequently diagnosed cancer with unfavorable clinical outcomes worldwide. circFNDC3B plays as a tumor suppressor in CRC, however, the mechanism of circFNDC3B in CRC remains ambiguous. The stem-like properties of CRC cells were detected by the evaluation of stemness markers, sphere formation assay and flow cytometry. qRT-PCR, FISH, IHC, and western blotting assessed the expression and localization of circFNDC3B, RNF41, ASB6, and stemness markers in CRC. The metastatic capabilities of CRC cells were examined by wound healing and Transwell assays, as well as in vivo liver metastasis model. Bioinformatics analysis, RNA immunoprecipitation (RIP), RNA pull-down assay and co-IP were used to detect the associations among circFNDC3B, FXR2, RNF41, and ASB6. Downregulated circFNDC3B was associated with unfavorite survival in CRC patients, and circFNDC3B overexpression suppressed CRC stemness and metastasis. Mechanistically, studies revealed that YTHDC1 facilitated cytoplasmic translocation of m6A-modified circFNDC3B, and circFNDC3B enhanced RNF41 mRNA stability and expression via binding to FXR2. circFNDC3B promoted ASB6 degradation through RNF41-mediated ubiquitination. Functional studies showed that silencing of RNF41 counteracted circFNDC3B-suppressed CRC stemness and metastasis, and ASB6 overexpression reversed circFNDC3B- or RNF41-mediated regulation of CRC stemness and metastasis. Elevated ASB6 was positively correlated with unfavorite survival in CRC patients. In vivo experiments further showed that circFNDC3B or RNF41 overexpression repressed tumor growth, stemness and liver metastasis via modulating ASB6. Taken together, m6A-modified circFNDC3B inhibited CRC stemness and metastasis via RNF41-dependent ASB6 degradation. These findings provide novel insights and important clues for targeted therapeutic strategies of CRC.

Trastuzumab plus docetaxel and capecitabine as a first-line treatment for HER2-positive advanced gastric or gastroesophageal junction cancer: a phase II, multicenter, open-label, single-arm study.

Gastric cancer (GC) is the second most common cancer in China. The ToGA study showed that trastuzumab in combination with fluoropyrimidine plus cisplatin prolonged overall survival (OS) in patients with human epidermal growth factor receptor 2 (HER2)-positive advanced GC (AGC). However, some patients may not be able to receive this regimen. We conducted a clinical study to evaluate the efficacy and safety of trastuzumab in combination with docetaxel+capecitabine (DX) in patients with HER2-positive AGC. This phase II, multi-center, open-label, single arm study enrolled patients with HER2-positive AGC who had not received prior treatment for metastatic disease. Patients were treated with a regimen of trastuzumab (8 mg/kg loading dose followed by 6 mg/kg, day 1), capecitabine (1000 mg/m2 twice daily, days 1-14) and docetaxel (60 mg/m2, day 1 for 6 cycles) every 3 weeks. The primary endpoint was progression-free survival (PFS) and the secondary endpoints were objective response rate (ORR), OS and safety profiles. Sixty-seven patients with AGC were enrolled from 14 centers. 64 were included in the full analysis set (FAS). The median PFS was 8.1 months (95% confidence interval [CI]: 5.6-12.8) and the median OS was 20.9 months (95% CI: 15.1-33.0). Response was evaluated in 59 patients. The ORR was 67.8%. The most common adverse events of Grade ≥3 were neutropenia, leukopenia, hand-foot syndrome, febrile neutropenia and anemia. We concluded that combination treatment with trastuzumab and DX was well-tolerated and highly effective in patients with HER2-positive AGC, and may offer an alternative to current treatments.

BACH1 promotes the progression of human colorectal cancer through BACH1/CXCR4 pathway.

The present study was to investigate clinical significance, biological functions and underlying mechanisms of BTB Domain and CNC Homolog 1(BACH1) deregulation in human colorectal cancer (CRC). The result showed that BACH1 upregulation was significantly associated with enhanced tumor invasion (P = 0.014) and gender (P = 0.028) of CRC patients. Kaplan-Meier method results showed that the overall survival of CRC patients with high BACH1 mRNA expression was markedly shorter than those with low expression (P = 0.015), and multivariate analyzes results showed that BACH1 was an independent prognostic predictor for CRC patients (P = 0.049). In vitro studies revealed that BACH1 efficiently promoted invasion and migration of CRC cell line. In vitro studies proved that the HCT116 cell stably expressing BACH1 formed significantly larger tumor nodules and remarkably accelerated tumor xenografts growth. In addition, Immunohistochemical scores of CD31 and Vimentin were significantly higher than those of the control group. Finally, correlation analysis indicated that BACH1 expression was positively correlated with C-X-C Motif Chemokine Receptor 4(CXCR4) in tumor tissues and cell lines. Together, BACH1 serves as an oncogene to promote CRC progression and an independent prognostic factor for survival and metastasis. BACH1 may inhibit the progression of CRC through BACH1/CXCR4 pathway.

Metastasis-associated in colon cancer-1 in gastric cancer: Beyond metastasis.

Metastasis-associated in colon cancer-1 (MACC1) is an oncogene that was first identified in colon cancer. The upstream and downstream of MACC1 form a delicate regulatory network that supports its tumorigenic role in cancers. Multiple functions of MACC1 have been discovered in many cancers. In gastric cancer (GC), MACC1 has been shown to be involved in oncogenesis and tumor progression. MACC1 overexpression adversely affects the clinical outcomes of GC patients. Regarding the mechanism of action of MACC1 in GC, studies have shown that it promotes the epithelial-to-mesenchymal transition and accelerates cancer metastasis. MACC1 is involved in many hallmarks of GC in addition to metastasis. MACC1 promotes vasculogenic mimicry (VM) via TWIST1/2, and VM increases the tumor blood supply, which is necessary for tumor progression. MACC1 also facilitates GC lymphangiogenesis by upregulating extracellular secretion of VEGF-C/D, indicating that MACC1 may be an important player in GC lymphatic dissemination. Additionally, MACC1 supports GC growth under metabolic stress by enhancing the Warburg effect. In conclusion, MACC1 participates in multiple biological processes inside and outside of GC cells, making it an important mediator of the tumor microenvironment.

[Establishment of BGC-823/pBaBb-puro-MACC1 gastric cancer cell line stably expressing MACC1 and its tumor-related gene expression profiles].

OBJECTIVE: To establish a gastric cancer cell line with stable expression of metastasis-associated in colon cancer 1 (MACC1) and detect the changes in tumor-related gene expression profiles for investigating the possible regulation mechanisms between MACC1 and the differentially expressed genes. METHODS: The full-length MACC1 cDNA was amplified from human embryonic kidney 293FT cells and cloned into the pBaBb-puro vector. The recombinant pBaBb-puro-MACC1 expression vector, after identification with restriction enzyme digestion, was transfected into 293FT cells, and the expression of fluorescent reporter gene was observed. pBaBb-puro-MACC1 vector was transfected into human gastric cancer BGC-823 cell line to establish BGC-823/pBaBb-puro-MACC1 cell line stably expressing MACC1. Quantitative RT-PCR and Western blotting were used to detect MACC1 expression in both BGC-823/pBaBb-puro-MACC1 and control BGC-823 cells. High-throughout cDNA microarray was used to screen the effects of MACC1 on the gene expression profiles of gastric cancer cells. RESULTS: The recombinant pBaBb-puro-MACC1 plasmid was successfully constructed and verified by PCR and sequencing. BGC-823/pBaBb-puro-MACC1 cells showed significantly increased MACC1 mRNA expression as compared with the control cells. The results of cDNA microarray identified 33 up-regulated and 24 down-regulated genes in the cells after MACC1 transfection involved were in various cellular functions. CONCLUSION: The established BGC-823/pBaBb-puro-MACC1 gastric cancer cell line show some important molecular changes caused by MACC1.

Cancer of the gastrointestinal tract results in a restricted T-cell repertoire dependent upon tumor differentiation.

We investigated the influence of tumor tissue differentiation on the diversity of TCR repertoire. CDR3 spectratypes of CD4(+) and CD8(+) T cell subsets were analyzed from 27 patients with gastrointestinal tract tumors exhibiting varying degrees of differentiation. A CDR3 spectratype complexity scoring system was used to quantify the diversity of TCR repertoire. Each patient was matched with an age-matched healthy group to control for age variability. Results show that the complexity scores (TCR repertoire diversity) have a significant correlation with the degree of tumor differentiation, which provides useful information for understanding immune response in cancer patients.

Normalization of T cell receptor repertoire diversity in patients with advanced colorectal cancer who responded to chemotherapy.

To investigate the correlation between normalization of T cell receptor (TCR) repertoire and remission of advanced colorectal cancer. Forty-one patients were randomly assigned to receive either folinic acid/fluorouracil/irinotecan alone (n = 20) or folinic acid/fluorouracil/irinotecan in combination with recombinant human endostatin (n = 21). Efficacy and toxicity were evaluated, and changes in TCR repertoire diversity were assessed by detecting the spectratypes of TCR complementarity-determining region three before and after several cycles of therapy. A scoring system was used to quantify changes in the TCR repertoire over time. The results demonstrated that the TCR repertoire exhibited a higher degree of normalization among patients undergoing remission relative to patients experiencing tumor progression. The results of the current study showed a positive correlation between TCR repertoire normalization and remission of colorectal cancer, suggesting that dynamic monitoring of TCR repertoire diversity may have potential prognostic value in the clinical setting.

KRAS and PIK3CA but not BRAF genes are frequently mutated in Chinese cholangiocarcinoma patients.

Cholangiocarcinoma (CCA) is a rare but lethal malignancy arising from the biliary tract epithelium. It has a poor prognosis largely due to the difficulties of early diagnosis and the lack of effective therapies. It is thus imperative to develop new and effective treatments for CCA, which depends heavily on the mechanistic understanding of the disease. Previous studies have suggested that somatic mutations in KRAS, BRAF, and PIK3CA genes are frequently found in several types of human cancers including colon, breast, and lung carcinomas as well as CCA. Yet, the frequency and the involvement of these oncogenic mutations in CCA in Chinese population have not been investigated. In this study, we evaluated the hotspot mutations of KRAS, BRAF, and PIK3CA genes in 34 Chinese CCA patients. Sequencing analysis revealed 13 (38.2%) and 11 (32.4%) patients bearing KRAS and PIK3CA mutations, in which two (5.9%) of them harbored both KRAS and PIK3CA mutations. Surprisingly, no BRAF mutation was detected in all 34 CCA samples. Our findings indicate that somatic mutations in KRAS and PIK3CA but not BRAF oncogenes are closely associated with the development of CCA in Chinese population and provide new potential targets for future therapeutic treatments of the disease.

[Evaluation of tumor angiogenesis using microbubbles conjugated with RGD peptides and contrast enhanced ultrasound].

OBJECTIVE: To assess the feasibility of usage of microbubbles conjugated with RGD peptides and contrast enhanced ultrasound (CEU) in detection of tumor angiogenesis. METHODS: Lipid microbubbles (MB) were prepared, and the RGD peptides were covalently conjugated to the lipid shell of MB (MB(RGD)). Six nude mice with tumor created by dorsal inoculation of HepG2 tumor cells were used as the test group. Six nude mice without tumor were served as the control group. 10 minutes after bolus injection of MB and MB(RGD) randomly (30 min interval) via a tail vein catheter, CEU was performed on the tumors of the test group and the thigh skeletal muscles of control group. The video intensity (VI) of tumors and the skeletal muscles were measured. The tumors and the skeletal muscles were harvested for immunohistochemical examination. RESULTS: Only a slight contrast enhancement of the tumor was seen with MB, and the VI was 5.33 ± 1.71. While a remarkable enhancement of the tumor was observed after injection of MB(RGD). The VI was up to 17.03 ± 3.58, 3.18 folds higher as compared with that obtained by injection of MB (P < 0.05). As expected, there were no obvious contrast enhancement of the skeletal muscles with both MB(RGD) and MB. There was a high expression of αvß3-integrin in tumor neovascular endothelium, however, no apparent expression of αvß3-integrin was observed in the skeletal muscle vascular endothelium. CONCLUSION: CEU with MB(RGD) can be used to effectively evaluate the angiogenesis of tumors, and it may greatly contribute to the early judgement of the nature of tumor.

Local recurrence of hepatocellular carcinoma after radiofrequency ablation.

A 51-year-old Chinese male with a 20-year history of hepatitis B was diagnosed with hepatocellular carcinoma in the right anterior portion of the liver, sized 3.5 cm × 3.2 cm, and was treated with radiofrequency ablation (RFA) on December 18, 2001. The patient did not receive antiviral therapy for hepatitis B virus after RFA. The treated lesion reduced gradually and reached its minimum size of 1.7 cm × 1.5 cm seven years later on November 18, 2008. However computed tomography findings revealed that a recurrence lesion of 6.0 cm × 4.8 cm which was histologically confirmed overlapped the previous treated lesion at the 8th year on December 3, 2009. Although recurrence at 8 years after curative RFA is a rare event, such a possibility must be kept in mind. To find and treat the recurrence lesion promptly, long-term and close monitoring is warranted after RFA. Meanwhile, the recurrence-prevention therapy is as important as close monitoring for those patients with a history of hepatitis B.

[Ultrasound-mediated microbubble destruction enhances LMP-1 gene transfection into dendritic cells in vivo].

OBJECTIVE: To investigate the transfection efficiency and the optimal conditions of delivering latent membrane protein-1 (LMP-1) gene to dendritic cells (DCs) by ultrasound exposure combined with contrast agent. METHODS: Human DCs were cultured in vivo and transfected with the recombinant plasmid pEGFP-C3-LMP1 under varying conditions including ultrasound intensities, exposure time and microbubble contrast agent concentration. The transfection efficiency was assessed by fluorescent microscopy and flow cytometry, and the cell viability by trypan blue exclusion test. RESULTS: An exposure time of 60 s at MI 1.0 with a microbubble contrast agent concentration of 20% resulted in the optimal effect of delivering the recombinant plasmid pEGFP-C3-LMP1 into the DCs, with a transfection efficiency of (14.37∓2.12)%. Over 90% of the transfected cells were viable after the transfection. CONCLUSION: Microbubble contrast agent combined with ultrasound exposure can enhance the delivery of recombinant plasmid pEGFP-C3-LMP1 into the DCs.

[Short-term therapeutic effect and safety of endostar combined with XELIRI regimen in the treatment of advanced colorectal cancer].

OBJECTIVE: To evaluate the short-term efficacy and toxicity of endostar in combination with XELIRI as the second-line treatment for advanced colorectal cancer. METHODS: Twenty-one patients with advanced colorectal cancer were treated with intravenous infusion of endostar (15 mg/day for 14 consecutive days) and irinotecan (250 mg/m(2), single dose on the first day), and oral administration of capecitabine (1.0 mg/m(2), twice daily for 14 days), and the treatment cycle was repeated every 21 days. The efficacy and toxicity of the treatments were evaluated according to RECIST and NCI-CTCAE3.0 standard, respectively. RESULTS: The overall response rate was 9.5% in these patients, with a median time to progression (mTTP) of 3.9 months. The main adverse effects associated with the treatment included leucopenia, nausea/vomiting and peripheral neuritis. CONCLUSION: Endostar combined with XELIRI is effective and safe as the second-line treatment for advanced colorectal cancer, and further clinical investigation is warranted.

Dynamic monitoring the TCR CDR3 spectratypes in patients with metastatic CRC treated with a combination of bevacizumab, irinotecan, fluorouracil, and leucovorin.

In the present study, either modified IFL regimen (modified irinotecan, fluorouracil and leucovorin, mIFL) alone or in combination with bevacizumab was used to treat patients with metastatic colorectal cancer (CRC). Treatment efficacy was assessed using coupled tomography imaging diagnosis. The toxicity accompany with treatment was evaluated, as well as T cell receptor (TCR) repertoire before and several cycles after therapy was dynamically monitored by analyzing the complementarity-determining region 3 (CDR3) length distribution within CD4(+) and CD8(+) T cell subsets. The degrees of normalization of the T cell repertoire in CRC patients treated with the two methods were compared. The results showed that mIFL combined with bevacizumab was more effective in treating patients with metastatic CRC, and was accompanied by an increase in side effects such as proteinuria and hematuria. An even more restricted CDR3 profile in patients with metastatic CRC compared with healthy control has been detected. A prominent usage of TCR beta chain variable (BV) gene BV12 and BV16 families within the CD4(+) T cell subset and BV19 and BV21 families within the CD8(+) T cell subset have been found before treatment. Moreover, CD8(+) T cells showed more restricted patterns than CD4(+) T cells, especially in patients before treatment. For patients with stable disease (SD) or partial remission (PR) after treatment, a less restricted CDR3 profile in post-treatment compared with pre-treatment has been found, but the opposite result was observed for patients with progressive disease (PD). The less restricted CDR3 pattern suggested a trend toward normalization of the TCR repertoire. The normalization of TCR repertoire significantly increased in patients treated with mIFL in combination with bevacizumab, but slightly in patients treated with mIFL alone. The results demonstrate a positive correlation between post-therapy TCR repertoire normalization and remission of metastatic CRC.

[Clinical value of (18)F-FDG positron emission tomography-computed tomography in local liver neoplasm ablation].

OBJECTIVE: To assess the value of (18)F-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) in ultrasound-guided local ablation of malignant liver tumors. METHODS: Thirteen patients with 35 local residual tumor foci following previous tumor ablation underwent (18)F-FDG PET-CT and ultrasound-guided local ablation with intratumoral alcohol injection. RESULTS: After the second local ablation guided by (18)F-FDG PET-CT and ultrasound, radioactive defects were detected in the corresponding location in 31 of the 35 residual foci, and after the third local ablation, the other 4 foci also showed radioactive defects. CONCLUSION: (18)F-FDG PET-CT can sensitively and accurately identify tissue necrosis and residual tumors, and serves as an excellent approach for ultrasound-guided local ablation of local residual tumors.

[Clinical significance of VEGF levels in serums of colorectal cancer patients at stage IV].

OBJECTIVE: To investigate the clinical significance of vascular endothelial growth factor (VEGF) levels in serums of colorectal cancer patients at stage IV. METHODS: Using enzyme linked immunosorbent assay (ELISA) to detect the VEGF levels in serums of 45 colorectal cancer patients at stage IV, and 20 healthy served as normal control. RESULTS: The mean concentration of VEGF in 45 colorectal cancer patients at the 7 day after operation were significantly lower than that before operation (P<0.01). The mean concentration of VEGF in the patients who benefit from bevacizumab showed no statistical difference from the levels of who did not benefit (P=0.554). CONCLUSION: The VEGF levels in colorectal patients at stage IV are lowed as the load of tumor decrease. The circulating levels of VEGF seem not predict the response to bevacizumab in colorectal cancer patients at stage IV.

[rAAV/BA46-transfected dendritic cells can induce specific cellular immunity].

OBJECTIVE: To study the feasibility of transfecting breast cancer BA46 gene into dendritic cells (DCs) using adeno-associated virus (AAV) to induce specific cellular immunity. METHODS: Mononuclear cells (DC precursor) were isolated from the peripheral blood of healthy donors by density gradient centrifugation and infected with rAAV/BA46/Neo virus stock (transfection group) or pulsed with 293 cell lysate (control group). In both groups, maturation of the DC precursor was induced by granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and tumor necrosis factor-alpha(TNF-alpha). On day 7, the DCs were collected and mixed with T cells at the ratio of 1 to 20 to induce cytotoxic T lymphocytes (CTL). The capacity of the DCs in stimulating T lymphocyte proliferation was assessed using (3)H-thymidine incorporation assay. The expressions of interferon-gamma (IFN-gamma), IL-4, CD4, CD8, CD25 and CD69 in the CTLs were analyzed with cytometry, and the cytotoxicity of the CTLs was evaluated with (51)Cr-release assay using BA46-positive breast cancer cell line Hs578T as the target. RESULTS: The DCs transfected with BA46 gene exhibited potent capacity to stimulate T lymphocyte proliferation. The CTL population induced by the transfected DCs expressed high levels of CD8, CD69 and IFN-gamma, and showed strong cytotoxicity against BA46-positive breast cancer cell line Hs578T, which was BA46 antigen-specific and MHC-limited. CONCLUSION: The success in BA46 gene transfer in the DCs that induce specific cellular immunity provides the experimental basis for breast cancer immunotherapy using genetically modified cells.

[Matrine-induced apoptosis in human colon adenocarcinoma SW620 cells].

OBJECTIVE: To investigate the effects of matrine on the cell cycle and apoptosis in human colon adenocarcinoma SW620 cells and explore the possible mechanisms. METHODS: The effect of matrine on cell proliferation was assessed using MTT assay, and the cell cycle arrest induced by matrine was determined by flow cytometry. The changes of cell morphology were observed through optical microscope, fluorescence microscope and electron microscope, and the cell apoptosis was detected using Annexin V-FITC apoptosis assay. RESULTS: Matrine inhibited the proliferation of SW620 cells in a dose- and time-dependent manner. Compared with the control group, the matrine-treated cells showed increased cell percentage arrested in G 0/G1 phase with decreased S-phase cells. Morphologically, the SW620 cells treated with matrine exhibited cell shrinkage, cell size reduction, plasma condensation, cytoplasmic vacuolar changes, and formation of apoptotic body with also the presence of the signet-ring cells, all typical of apoptotic cells. CONCLUSION: Matrine exposure of SW620 cells inhibits the cell proliferation, causes cell cycle arrest at G 0/G1 phase, and induces apoptosis in a dose- and time- dependent manner.

[Effect of percutaneous chemotherapy pump placement for portal vein chemotherapy on hepatic metastasis of colorectal cancer].

OBJECTIVE: To evaluate safety and effect of percutaneous chemotherapy pump placement for portal vein chemotherapy in management of colorectal cancer with hepatic metastasis. METHODS: Twenty-three cases of colorectal cancer with liver metastasis were treated with percutaneous chemotherapy pump placement for portal vein chemotherapy, and the therapeutic effect of this treatment was observed. RESULTS: Partial remission of the hepatic lesions was achieved in 13 (56.5%) of the patients following the treatment, and the condition was stabilized in 5 patients (21.7%). No severe complications were observed in these patients. CONCLUSION: Percutaneous chemotherapy pump placement for portal vein chemotherapy can be safe and effective for management of hepatic metastasis of colorectal cancer.

[Efficacy of Avastin in combination with irinotecan for metastatic colorectal cancer].

OBJECTIVE: To evaluate the efficacy of Avastin in combination with irinotecan for metastatic colorectal cancer. METHODS: Ninety patients were randomly divided into 3 equal groups to receive Avastin plus irinotecan (group A), FOLFIRI (group B) and FOLFOX7 (group C) for two cycles, respectively. The response rate and changes in tumor maker levels were observed. RESULTS: The tumor response rate was 43.3% in group A, 27.7% in group B and 30.0% in group C. The disease control rate (complete response+partial response+stable disease) was 80% in group A, 53.3% in group B and 50.0% in group C. Obvious changes in tumor marker levels were observed in the 3 groups after treatment, which were most conspicuous in group A (P<0.05). CONCLUSION: The addition of Avastin to irinotecan chemotherapy results in significant improvement of clinical efficacy in patients with metastatic colorectal cancer.

Clinical study of Photofrin photodynamic therapy for the treatment of relapse nasopharyngeal carcinoma.

OBJECTIVES: To evaluate the clinical response and adverse effects of Photofrin photodynamic therapy (PDT) in patients with relapse nasal pharyngeal cancer. METHODS: Thirty patients with relapse nasal pharyngeal cancer were randomly divided into PDT group and chemotherapy group. In PDT group, patients received intravenous administration of Photofrin (2mg/kg b.w.) and 48h later light (200-300J/cm) was delivered by a 630nm diode laser through a cylinder diffuser under endoscopic assistance. Two days after PDT the necrotic tissues were removed and newly identified sites were subject to another round of light irradiation. In chemotherapy group, the routine cisplatin and 5-fluorouracil (DDP/5-FU) remedy was used. Endoscopic and radiological examinations were performed during 6 months follow-up. The Karnofsy Score was used to evaluate the quality of life. RESULTS: The local response and nasal cavity obstruction remission rate in PDT group were better than that in chemotherapy group. The Karnofsy Score was also improved in PDT group. CONCLUSION: This pilot study suggests that Photofrin PDT is effective and safe in treatment of advanced nasal pharyngeal cancer and management of nasal obstruction.