Tim-3 fosters HCC development by enhancing TGF-β-mediated alternative activation of macrophages

OBJECTIVE

Tumour-associated macrophages (TAMs) and their alternative activation contribute greatly to the development of hepatocellular carcinoma (HCC). Tim-3 is highly expressed on macrophages and regulates macrophage functions in several conditions. However, whether Tim-3 is involved in the activation and the function of TAMs has not been reported.

DESIGN

Tim-3 expression in HCC samples was evaluated by flow cytometry, immunohistochemistry and confocal analysis. We analysed the effects of Tim-3 knockdown on macrophages in growth of H22 tumour homografts in BALB/c mice. Tim-3 interference was performed by neutralising antibody, small interfering RNA or short hairpin RNA-expressing lentivirus. Cytokine production was evaluated by reverse transcription PCR, ELISA or Cytometric Bead Array. The effects of Tim-3 interference in macrophages were examined with regard to alternative activation of macrophages and proliferation and migration of Hepa1-6 cells. Cell growth curve, colony formation and transwell assays were involved to estimate cell proliferation and migration.

RESULTS

Tim-3 expression was significantly increased in both peripheral blood monocytes and TAMs in patients with HCC. The Tim-3 expression in monocytes/TAMs strongly correlated with higher tumour grades and the poor survival of patients with HCC. Consistently, HCC conditioned medium or transforming growth factor-β fostered Tim-3 expression and the alternative activation of macrophages. Moreover, Tim-3 interference in macrophages significantly inhibited the alternative activation of macrophages and suppressed HCC cell growth both in vitro and in vivo. Blocking interleukin 6 reversed the Tim-3-mediated effects on HCC cell growth in vitro.

CONCLUSIONS

Tim-3 displays critical roles in microenvironment-induced activation and protumoral effects of TAMs in HCC. Interference of Tim-3 might be great potential in HCC therapy.

THE UPTAKE OF FLUORESCENT LABELLED PROTEINS BY NORMAL AND TUMOUR TISSUES IN VIVO

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INDUCTION OF HEPATOMAS IN CBA-CB-SE MICE BY HYDRAZINE SULPHATE AND THE LACK OF EFFECT OF CROTON OIL ON TUMOUR INDUCTION IN BALB-C-CB-SE MICE

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AZO-DYE CARCINOGENESIS: RIBONUCLEOTIDES AND RIBONUCLEASES

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THE VALUE OF JIRGL'S FLOCCULATION TEST IN THE DIAGNOSIS OF JAUNDICE

Jirgl's serum flocculation reaction was examined in a series of 121 patients with varying types of liver disease. Positive results were found in 90% of patients with proven extrahepatic obstructive jaundice. Strongly positive reactions were also obtained in primary biliary cirrhosis and chlorpromazine jaundice. One out of three cases of ;cholestatic' hepatitis gave a weakly positive reaction and the test may be of value in the diagnosis of this condition and in the rare recurrent conjugated hyperbilirubinaemia in which it is also negative.Eighty-four per cent of cases of portal cirrhosis were negative and the finding of a positive result in this condition may indicate the presence of a hepatoma.No correlation could be found either in intra- or extrahepatic obstructive jaundice between the degree of flocculation present and the severity of the obstruction as judged by serum bilirubin and alkaline phosphatase levels.

THE ESTIMATION OF THE OXIDIZED AND REDUCED FORMS OF THE NICOTINAMIDE NUCLEOTIDES

1. A method is described for the determination of the oxidized and reduced forms of the nicotinamide nucleotides by measuring the rate of the oxygen uptake with an oxygen electrode in a system in which the nucleotide acts as the rate-limiting carrier in a cyclic system. 2. The method permits the measurement of quantities as low as 0.02mug. of NAD(+) or NADH or 0.01mug. of NADP(+) or NADPH. 3. The method permits the measurement of the nucleotides in extracts that contain non-specific reducing substances, coloured compounds or fluorescent materials, e.g. green leaves. 4. The results obtained by the present method are compared with those reported in the literature.

EFFECTS OF WHOLE BODY IRRADIATION AND OF PARTIAL HEPATECTOMY ON THE LIVER LESIONS INDUCED IN RATS BY A SINGLE DOSE OF RETRORSINE, A PYRROLIZIDINE (SENECIO) ALKALOID

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THE REPLICATION TIME AND PATTERN OF CARCINOGEN--INDUCED HEPATOMA CELLS

The replication time and pattern have been investigated in hepatoma cells induced by feeding 3'Me-DAB to male rats for 5 months. With the use of tritiated thymidine as a DNA label along with autoradiography, mitotic nuclear labeling has been studied 0.5 to 72 hours after the administration of the label. The following time intervals have been estimated: replication time, 31 hours; DNA synthesis, 17 hours; G(2) plus Mitosis, 2 hours; G(1), 12 hours. Only about 8 per cent of the tumor cell (interphase) population is "flash" labeled, following a single dose of 50 microC of H(3)TDR. This group of cells has been followed through three cycles of division. The repeated rhythmic passage of tumor cells through cell division is similar to that previously reported for normal liver cells in the growing rat. However, tumor cells have longer replication and DNA synthesis times. In addition, the several time intervals studied vary more in the tumor cell population than they do in the growing normal cell population.