The function of the spleen in tumor development has been investigated for years. The relationship of the spleen with hepatocellular carcinoma (HCC), a huge health burden worldwide, however, remains unknown. The present study aimed to examine the effect of splenectomy on the development of HCC and the possible mechanism. Mouse hepatic carcinoma lines H22 and Hepa1-6 as well as BALB/c and C57 mice were used to establish orthotopic and metastatic mouse models of liver cancer. Mice were divided into four groups, including control group, splenectomy control group (S group), tumor group (T group) and tumor plus splenectomy group (T+S group). Tumor growth, metastases and overall survival were assessed at determined time points. Meanwhile, myeloid-derived suppressor cells (MDSCs) were isolated from the peripheral blood (PB), the spleen and liver tumors, and then measured by flow cytometery. It was found that liver cancer led to splenomegaly, and increased the percentage of MDSCs in the PB and spleen in the mouse models. Splenectomy inhibited the growth and progression of liver cancer and prolonged the overall survival time of orthotopic and metastatic models, which was accompanied by decreased proportion of MDSCs in the PB and tumors of liver cancer-bearing mouse. It was suggested that splenectomy could be considered an adjuvant therapy to treat liver cancer.
Animals ; Carcinoma, Hepatocellular ; physiopathology ; surgery ; Cell Line, Tumor ; Flow Cytometry ; Humans ; Liver Neoplasms ; physiopathology ; surgery ; Mice ; Myeloid-Derived Suppressor Cells ; pathology ; Neoplasms, Experimental ; physiopathology ; surgery ; Spleen ; physiopathology ; surgery ; Splenectomy ; methods

OBJECTIVE: To observe the micromorphological changes of ultrastructure, apoptosis-related proteins expression and tumor cell apoptosis after ablation with the high-intensity focused ultrasound (HIFU), and to explore the mechanisms responsible for the thermal and non-thermal effect.
 METHODS: Forty rabbits with hepatic VX2 tumors were randomly divided into a thermal group (n=20) and a non-thermal group (n=20), and were subjected to HIFU ablation with thermal or non-thermal condition, respectively. Five animals in each group were sacrificed on the 1st, 3rd, 7th or 14th day after the ablation. The changes of ultrastructure, apoptosis-related proteins expression and tumor cell apoptosis were detected.
 RESULTS: The results of transmission electron microscope (TEM) revealed more severe injury on tissue and cells in the non-thermal group than that in the thermal group. The changes of apoptosis-related proteins expression and tumor cell apoptosis in transient zone were significantly different in comparison with that in the ablated area or peripheral area between the two groups. The expression of vascular endothelial growth factor (VEGF) was at low level on the 1st and 3rd day and elevated gradually on the 7th and 14th day, with no significant difference (all P>0.05). The expression of caspase-3 reached peak on the 3rd day and decreased on the 7th and 14th day. It was significantly higher in the non-thermal group than that in the thermal group on the 3rd and 7th day (all P<0.05). The expression of NF-κB was elevated from the 3rd day and reached peak on the 7th day while decreased on the 14th day. There was no significant difference at every time point between the 2 groups (all P>0.05). The apoptosis index in the non-thermal group and the thermal group on the 3rd and 7th day were (28.60±1.14)% vs (21.80±1.92)% and (21.00±1.58)% vs (14.80±1.48)%, respectively. It was higher in the non-thermal group than that in the thermal group (both P<0.01).
 CONCLUSION Both the thermal and the non-thermal effect of HIFU can induce apoptosis in transient zone, but the latter have a stronger effect.
Animals ; Apoptosis ; Caspase 3 ; metabolism ; High-Intensity Focused Ultrasound Ablation ; Liver Neoplasms ; pathology ; ultrastructure ; NF-kappa B ; metabolism ; Neoplasms, Experimental ; pathology ; ultrastructure ; Rabbits ; Vascular Endothelial Growth Factor A ; metabolism

Tumors are believed to consist of a heterogeneous population of tumor cells originating from rare cancer stem cells (CSCs). However, emerging evidence suggests that tumor may also originate from non-CSCs. To support this viewpoint, we are here to present definitive evidence indicating that the number of tumorigenic tumor cells is greater than that of CSCs in tumor, and tumor can also derive from non-CSCs. To achieve this, an idealized mathematical model was employed in the present study and theoretical calculation revealed that non-CSCs could initiate the occurrence of tumor if their proliferation potential was adequate. Further, experimental studies demonstrated that 17.7%, 38.6% and 5.2% of tumor cells in murine B16 solid melanoma, H22 hepatoma and Lewis lung carcinoma, respectively, were potentially tumorigenic. Thus, based on the aforementioned findings, we propose that the scarce CSCs, if exist, are not the sole source of a tumor.
Algorithms ; Animals ; Carcinogenesis ; pathology ; Carcinoma, Lewis Lung ; pathology ; Cell Differentiation ; Cell Line, Tumor ; Cell Proliferation ; Liver Neoplasms, Experimental ; pathology ; Melanoma, Experimental ; pathology ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Models, Biological ; Neoplasms, Experimental ; pathology ; Neoplastic Stem Cells ; pathology ; Time Factors ; Tumor Stem Cell Assay ; methods

OBJECTIVETo study the effect of spleen lymphocytes on the splenomegaly by hepatocellular carcinoma-bearing mouse model.

METHODSCell counts, cell cycle distribution, the percentage of lymphocytes subsets and the levels of IL-2 were measured, and two-dimensional gel electrophoresis (2-DE) was used to investigate the relationship between spleen lymphocytes and splenomegaly in hepatocellular carcinoma-bearing mice.

RESULTSCompared with the normal group, the thymus was obviously atrophied and the spleen was significantly enlarged in the tumor-bearing group. Correlation study showed that the number of whole spleen cells was positively correlated with the splenic index. The cell diameter and cell-cycle phase distribution of splenocytes in the tumor-bearing group showed no significant difference compared to the normal group. The percentage of CD3+ T lymphocytes and CD8+ T lymphocytes in spleen and peripheral blood of tumor-bearing mice were substantially higher than that in the normal mice. Meanwhile, the IL-2 level was also higher in the tumor-bearing group than in the normal group. Furthermore, two dysregulated protein, β-actin and S100-A9 were identified in spleen lymphocytes from H22-bearing mice, which were closely related to cellular motility.

CONCLUSIONIt is suggested that dysregulated β-actin and S100-A9 can result in recirculating T lymphocytes trapped in the spleen, which may explain the underlying cause of splenomegaly in H22-bearing mice.

Animals ; Carcinoma, Hepatocellular ; complications ; Cell Cycle ; Female ; Liver Neoplasms ; complications ; Lymphocytes ; physiology ; Mice ; Mice, Inbred ICR ; Neoplasms, Experimental ; therapy ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Spleen ; cytology ; pathology ; Splenomegaly ; etiology ; therapy ; Thymus Gland

OBJECTIVETo establish a modified rat model of liver cancer with concurrent cirrhosis for the study of carcinogenesis characteristics and drug intervention of liver cancer.

METHODSFifty male Wistar rats weighing 100-120 g were randomly divided into normal control group (20 rats) and model group (30 rats). In the model group, the rats were subjected to intraperitoneal injection of 50 mg/kg DEN N-diethylnitrosamine (DEN) twice a week for 4 consecutive weeks, followed then by weekly injections for another 10 weeks. The control rats received injections of 0.1 ml saline in the same manner. At 2, 4, 8, 12, 14, and 18 weeks, 3 rats from each group were sacrificed for assessing tumor formation and liver cirrhosis.

RESULTSLiver cancer with concurrent cirrhosis was induced successfully after 14 weeks of DEN injections. At the 14th week, 3 out of the 5 rats were found to have cirrhosis and LC, and at the 18th week, all the 3 rats examined had cirrhosis and liver cancer. The total carcinogenesis rate in the rats was 75% at 18 weeks with an overall mortality of 33%.

CONCLUSIONThis approach to establishing rat models of liver cancer with concurrent cirrhosis requires simple operation, shortens the time of carcinogenesis, and ensures a high success rate of carcinogenesis and a low mortality rate. The carcinogenesis characteristics in this model are similar to those in human.

Animals ; Liver Cirrhosis, Experimental ; complications ; pathology ; Liver Neoplasms, Experimental ; etiology ; pathology ; Male ; Rats ; Rats, Wistar

This study is to investigate the anti-tumor activities of a novel cyclophosphamide derivate 4, 6-diphenyl cyclophosphamide (9b) in vivo and in vitro, and its possible mechanism of action. The inhibitory effects of 9b on human hepatoma cell line HepG2, human breast carcinoma cell line MCF-7 and human myeloid leukemia cell line K562 were measured by MTT assay in vitro. Cell cycle distribution and apoptotic rate were evaluated by flow cytometry. To evaluate the anti-tumor effect of 9b in vivo, mouse model bearing inoculated H22 tumor was established. The results indicated that 9b could inhibit the proliferation of HepG2, MCF-7 and K562 cells in a dose and time dependent manner. The ICo50 values of 9b were 32.34 micromol.L-1 to HepG2 cells, 87.07 micromol.L-1 to MCF-7 cells and 149.10 micromol.L-1 to K562 cells after incubation for 48 h. The results of flow cytometry indicated that after being treated for 48 h with different concentrations of 9b, the ratios of HepG2, MCF-7 cells at the Go/G1 phase and K562 cells at the G0/Gl phase and G2/M phase increased significantly compared with control group, and the apoptotic rate increased with the increase of the concentration of 9b. 9b could significantly reduce tumor weight of H22 solid tumor mouse model in vivo. To summarize, 9b showed significantly anti-tumor activity in vivo and in vitro, of which the mechanism might be associated with the change of cell cycle distribution and induction of tumor cell apoptosis.
Animals ; Antineoplastic Agents, Alkylating ; chemistry ; pharmacology ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclophosphamide ; analogs & derivatives ; chemistry ; pharmacology ; Dose-Response Relationship, Drug ; Female ; Humans ; Inhibitory Concentration 50 ; Liver Neoplasms, Experimental ; pathology ; Male ; Mice ; Molecular Structure ; Random Allocation ; Tumor Burden ; drug effects

5-Flucytosine (5-FC) could be changed to 5-fluorouracil (5-FU) by cytosine deaminase (CD), the latter is able to kill cancer cells. However, there is no efficient method to deliver the CD gene into the tumor cells, which hampers the application of the suicide gene system. In this experiment, for the first time, the NDV has been utilized as a vector to deliver the CD gene into the cancer cells, the virus can infect the cancer cells specifically, replicate and assemble, while the cytosine deaminase is expressed. Then the CD converts the prodrug 5-FC into 5-FU to achieve the purpose of inhibiting tumor. Firstly, the whole genome of E. coli JM109 was extracted, and the CD gene was obtained by cloning method. Then the CD and IRES-EGFP were ligated into the pEE12.4 expression vector to become a recombinant pEE12.4IE-CD eukaryotic expression plasmid. The human liver cancer cells were transfected with the plasmid. The cells were treated with different concentrations of 5-FC, MTT method was used to determine the killing effect of CD/5-FC system on the human liver cancer cells. The cell deaths were 18.07%, 42.98% and 62.20% respectively when the concentrations of prodrug were at 10, 20 and 30 mmol x L(-1). In 5-FC acute toxicity experiment, Kunming mice were injected with different concentrations of 5-FC at intervals of 1:0.5. The LD50 of 5-FC through iv injection was determined by improved Karber's method, the LD50 was 507 mg x kg(-1) and the 95% confidence limit was 374-695 mg x kg(-1). According to the maximum LD0 dose of the LD50, the maximum safe dose was 200 mg x kg(-1). Body weight and clinic symptoms of the experimental animals were observed. These results laid the foundation to verify the antitumor effect and safety of CD/5-FC system in animal models. The CD gene was ligated into the NDV (rClone30) carrier, then the tumor-bearing animal was established to perform the tumor inhibiting experiment. The result showed that the recombinant rClone30-CD/5-FC system has a high antitumor activity in vivo. To summarize, CD gene has been cloned and its bioactivity has been confirmed in the mammalian cells. It is the first time in this study to utilize the recombinant NDV to deliver the CD gene into the tumor cells; our result proves the rClone30-CD/5-FC system is a potential method for cancer therapy.
Animals ; Antimetabolites, Antineoplastic ; metabolism ; pharmacology ; Cell Death ; drug effects ; Chick Embryo ; Cytosine Deaminase ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Flucytosine ; metabolism ; pharmacology ; Fluorouracil ; metabolism ; pharmacology ; Genetic Vectors ; Hep G2 Cells ; Humans ; Lethal Dose 50 ; Liver Neoplasms, Experimental ; pathology ; Mice ; Newcastle disease virus ; genetics ; Plasmids ; Recombinant Proteins ; genetics ; metabolism ; Transfection ; Tumor Burden ; drug effects

OBJECTIVETo assess the application of gray-scale contrast-enhanced ultrasound (CEUS) and contrast-enhanced spiral computed tomography (CECT) in detection of residual tumor after high intensity focused ultrasound (HIFU) ablation with microbubbles on rabbit hepatic VX2 tumors.

METHODSForty rabbits with hepatic VX2 tumors were randomly divided into three groups before ablation. Group I (n=10) served as sham ablation controls, rabbits in group II (n=15) and group III (n=15) were ablated using HIFU under the manipulation of computer. A bolus of 0.2 ml SonoVue solution was injected via ear marginal vein of rabbits in group III before ablation. Tumors were examined with CEUS and CECT before and within 3h after HIFU ablation. Necropsy and histopathological assessment were performed immediately after the completion of images evaluation.

RESULTSBefore ablation, intense arterial feeding vessels was detected in the tumors (77.5%,31/40 Compared with 52.5%,21/40) or the periphery of the tumors (22.5%,9/40 Compared with 47.5%,19/40) by CEUS and CECT, respectively. The tumors were characterized by quick wash-in and wash-out (high and rapid peak of enhancement in the arterial phase,followed by a fast decrease in enhancement level). The dose parameters used to achieve therapeutic effect in group III were significantly lower than those in group II(P<0.01). There were local residual viable tumor tissues due to incomplete ablation in 60.0% (9/15) of group II and 13.3% (2/15) of group III revealed by histopathology(P<0.05). The concordance rate of CECT and CEUS with histopathology on residual tumor detection was 27.3% and 81.8% (P<0.05), respectively.

CONCLUSIONThe administration of microbubble agent enhances the efficacy of HIFU on rabbit hepatic VX2 tumors. CEUS is more sensitive than CECT in detection of residual viable rabbit VX2 tumor after HIFU.

Animals ; Female ; High-Intensity Focused Ultrasound Ablation ; Liver Neoplasms, Experimental ; therapy ; Male ; Microbubbles ; Neoplasm, Residual ; diagnostic imaging ; pathology ; Phospholipids ; Rabbits ; Sulfur Hexafluoride ; Tomography, Spiral Computed ; Ultrasonography

OBJECTIVETo investigate the effect of enoyl coenzyme A hydratase-1 (Ech1) on the proliferation and invasion ability of mouse hepatocarcinoma Hca-P cells in vitro.

METHODSRecombinant pcDNA3.1(+)-Ech1 gene and pcDNA3.1(+) were transfected into Hca-P cells by cationic liposomes introduction. Clone of PEch1 cells that stably expressing Ech1 and clone of control Pvector cells were screened by G418. The Ech1 expression was identified subsequently by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The malignant behaviors of the cell lines were compared by proliferation, invasion and migration test.

RESULTSThe cell line Hca-P cells stably expressing Ech1 gene was constructed. The relative expression of Ech1 mRNA in the PEch1 group was 3.21 ± 0.43 and in the Pvector group was 1.44 ± 0.03, with a significant difference between the two groups (P = 0.029). The results of ELISA revealed that the expression of Ech1 protein was 0.140 ± 0.005 in the PEch1 group, 0.088 ± 0.003 in the Pvector group, and 0.078 ± 0.006 in the Hca-P group, showing a significant difference between the PEch1 group and the Pvector and Hca-P groups (P < 0.05). Transwell migration test showed that the number of penetrated cells in the PEch1 group was 143.00 ± 7.25 cells, significantly higher than that of the Pvector group (95.73 ± 3.88 cells) and un-treated Hca-1 group (106.67 ± 3.54 cells, both P < 0.05). The Transwell invasion assay showed that the number of penetrated cells was 77.20 ± 5.46 cells in the PEch1 group, significantly higher than 46.34 ± 4.35 cells in the Pvector group and 49.80 ± 5.21 cells in the un-treated Hca-1 group (both P < 0.05).

CONCLUSIONSThe results showed that overexpressed Ech1 in Hca-P cells may significantly increase the cell proliferation in a time-dependent manner. The up-regulation of Ech1 may increase to some extent the migration and invasion capacity of Hca-P cells. The efforts aiming at up-regulation of Ech1 expression may become a therapeutic target in the treatment of hepatocarcinoma.

Animals ; Carbon-Carbon Double Bond Isomerases ; genetics ; metabolism ; Cell Movement ; Cell Proliferation ; Liver Neoplasms, Experimental ; enzymology ; pathology ; Mice ; Neoplasm Invasiveness ; Plasmids ; RNA, Messenger ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; Transfection ; Tumor Cells, Cultured ; Up-Regulation

OBJECTIVETo construct a high metastatic potential human hepatocellular carcinoma (HCC) orthotopic transplantation model with palliative liver resection in nude mice.

METHODSA human HCC orthotopic nude mice model was established by administering a single inoculation of the highly metastatic MHCC97H tumor tissue (size 2 mm * 2 mm * 2 mm) into the left liver lobe. At day 14 post-inoculation, a random group of the mice received palliative liver resection; the unresected mice served as controls. Changes in expression levels of 113 genes with metastasis-related functions were evaluated in the residual HCC tissues. At day 35 post-resection, a random group of the mice were sacrificed by cervical dislocation and a comprehensive metastases examination was performed. The remaining mice were used to observe life span. All statistical analyses were performed by the SPSS v17.0 software, and significance was defined as P less than 0.05.

RESULTSThe nude mouse model of highly metastatic HCC with palliative liver resection was successfully established. Incidences of intrahepatic and abdominal metastases were higher in the palliative resected group (vs. unresected group: 11.7+/-4.7 vs. 6.3+/-2.8, t = -2.412, P less than 0.05 and 9.8+/-3.4 vs. 5.2+/-2.6, t = -2.641, P less than 0.05 respectively). In addition, the palliative resected group showed significantly enhanced pulmonary metastasis (vs. unresected group: 14.3+/-4.7 vs. 8.7+/-4.7, t = -2.348, P less than 0.05). Differential gene expression levels were found for MTSS1, TGFbl, SMAD2, IL-1b, and MMP7, and were situated in the central position of gene function net of residual HCC. The life-span of the palliative resected group was significantly longer than that of the unresected group (60.8+/-2.7 vs. 51.3+/-1.4 days, x2 = 12.850, P less than 0.01).

CONCLUSIONThe highly metastatic human HCC nude mouse model with palliative liver resection that was successfully constructed in this study represents a useful investigational tool to assess the biological characteristics of residual cancer and to screen therapeutic strategies.

Animals ; Carcinoma, Hepatocellular ; pathology ; surgery ; Disease Models, Animal ; Hepatectomy ; Humans ; Liver Neoplasms, Experimental ; pathology ; surgery ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Metastasis ; Neoplasm Transplantation ; Tumor Cells, Cultured