[Effects of Platelet-Rich Plasma-Derived Exosomes on Proliferation and Migration of Tendon Stem/Progenitor Cell].

Objective To investigate the effects of platelet-rich plasma-derived exosomes (PRP-Exos) on the proliferation and migration of tendon stem/progenitor cell (TSPC).Methods PRP-Exos were extracted through the combination of polymer-based precipitation and ultracentrifugation.The morphology,concentration,and particle size of PRP-Exos were identified by transmission electron microscopy and nanoparticle tracking analysis.The expression levels of surface marker proteins on PRP-Exos and platelet membrane glycoproteins were determined by Western blot analysis.Rat TSPC was extracted and cultured,and the expression of surface marker molecules on TSPC was detected using flow cytometry and immunofluorescence staining.The proliferation of TSPC influenced by PRP-Exos was evaluated using CCK-8 assay and EdU assay.The effect of PRP-Exos on the migration of TSPC was evaluated by cell scratch assay and Transwell assay.Results The extracted PRP-Exos exhibit typical saucer-like structures,with a concentration of 4.9×1011 particles/mL,an average particle size of (132.2±56.8) nm,and surface expression of CD9,CD63 and CD41.The extracted TSPC expressed the CD44 protein.PRP-Exos can be taken up by TSPC,and after co-cultured for 48 h,concentrations of 50 and 100 µg/mL of PRP-Exos significantly promoted the proliferation of TSPC (both P<0.001),with no statistical difference between the two concentrations (P=0.283).Additionally,after co-cultured for 24 h,50 µg/mL of PRP-Exos significantly promoted the migration of TSPC (P<0.001).Conclusion Under in vitro culture conditions,PRP-Exos significantly promote the proliferation and migration of rat TSPC.

[Human Platelet-Rich Plasma-Derived Exosomes Promote the Proliferation of Schwann Cells Cultured in Vitro].

Objective To investigate the effect of human platelet-rich plasma-derived exosomes(PRP-exos)on the proliferation of Schwann cell(SC)cultured in vitro. Methods PRP-exos were extracted by polymerization-precipitation combined with ultracentrifugation.The morphology of PRP-exos was observed by transmission electron microscopy,and the concentration and particle size distribution of PRP-exos were determined by nanoparticle tracking analysis.Western blotting was employed to determine the expression of the marker proteins CD63,CD81,and CD9 on exosome surface and the platelet membrane glycoprotein CD41.The SCs of rats were isolated and cultured,and the expression of the SC marker S100ß was detected by immunofluorescence staining.The fluorescently labeled PRP-exos were co-cultured with SCs in vitro for observation of their interaction.EdU assay was employed to detect the effect of PRP-exos on SC proliferation,and CCK-8 assay to detect the effects of PRP-exos at different concentrations(0,10,20,40,80,and 160 µg/ml)on SC proliferation. Results The extracted PRP-exos appeared as uniform saucer-shaped vesicles with the average particle size of(122.8±38.7)nm and the concentration of 3.5×1012 particles/ml.CD63,CD81,CD9,and CD41 were highly expressed on PRP-exos surface(P<0.001,P=0.025,P=0.004,and P=0.032).The isolated SCs expressed S100ß,and PRP-exos could be taken up by SCs.PRP-exos of 40,80,and 160 µg/ml promoted the proliferation of SCs,and that of 40 µg/ml showed the best performance(all P<0.01). Conclusions High concentrations of PRP-exos can be extracted from PRP.PRP-exos can be taken up by SCs and promote the proliferation of SCs cultured in vitro.

(E)-4-Bromo-N'-(2-chloro-benzyl-idene)benzohydrazide.

In the title compound, C(14)H(10)BrClN(2)O, the dihedral angle between the two benzene rings is 11.4 (2)°. In the crystal structure, mol-ecules are connected via inter-molecular N-H⋯O hydrogen bonds into one-dimensional chains running parallel to the c axis.

[A comparison of curative effects of percutaneous nephrostomy and open surgery in the management of postrenal acute renal failure].

OBJECTIVE: To investigate the effects and clinical value of percutaneous nephrostomy (PCN) in the management of postrenal acute renal failure (PARF). METHODS: The clinical data of 40 cases of PARF for the treatment of PCN and 20 cases with open surgery were retrospectively analyzed. RESULTS: The success rate of PCN was 100%, renal function of all patients was restored to normal range after 2-7 days of PCN, in whom 30 patients recovered. In 10 patients nephrostomy was prolonged, among them 2 patients had recurrent abdominal tumors, and 8 patients had cervical cancer in late phase. There was no death, and no complications except hematuria. In the open surgery group, renal function of 19 cases recovered to normal range after 2-7 days of drainage. Lung infection occurred in 3 patients after operation, and they recovered with antibiotic therapy. One patient died of multiple organ dysfunction failure (MOF). CONCLUSION: For PARF, PCN is preferable because of minimal trauma, less blood loss, as well as rapid recovery and better effect on recovery of renal function.

[Relationship between sensitivity of tumor cells to chemotherapeutic agent in vivo and in vitro: experiment with mouse lymphoma cells].

OBJECTIVE: To study the relationship of the sensitivity of tumor cells to chemotherapeutic agent between in vivo and in vitro. METHODS: Mouse lymphoma cells of the line E14 were cultured and melphalan resistant EL4 cell line (EL4/melphalan) was established by culturing EL4 cells with continuous low-concentration and intermittent gradually-increasing-concentration of melphalan in vitro. MTT assay was used to evaluate the drug sensitivity and the resistance index of the EL4/melphalan cells to melphalan was calculated. EL4/melphalan and EL4 cells of the concentration of 5 x 10(8)/L were inoculated separately into 20 C57BL/6 mice subcutaneously. 12 days later, the EL4 and EL4/melphalan tumor-bearing mice were randomly divided into 2 groups respectively, 5 mice in each group. Treatment groups were given 7.5 mg/kg melphalan intraperitoneally, and control groups were given the same volume of normal saline. The tumor size was observed every other day. RESULTS: Compared with the EL4 cells, the EL4/melphalan cells had no obvious changes morphologically. They could grow in RPMI 1640 medium containing 5 mg/ml melphalan. The resistance index was 2.87 against melphalan. After the treatment of melphalan of the dose 7.5 mg/kg, the tumor sizes of the treatment groups and control groups inoculated with both EL4 cells and the EL4/melphalan cells gradually decreased at the similar speed, and about one week later all tumors disappeared. However, the tumors of the control groups grew progressively and all the mice died at last. CONCLUSION: The chemotherapeutic effects of tumors in vivo have nothing to do with the effects of the chemotherapeutic agents on tumor cells in vitro. The tumor cells resistant to melphalan in vitro remain sensitive to the drug in vivo.

[Toxicity attenuation and efficacy potentiation effects of sijunzi decoction on bladder carcinoma treated by chemotherapy in mice].

OBJECTIVE: To investigate the toxicity attenuation and efficacy potentiation effects of Sijunzi decoction (SJZD) on bladder carcinoma treated by chemotherapy in mice. METHODS: T739 mice were randomly divided into 8 groups after subcutaneous inoculation of bladder carcinoma cells, the control group (A); two mitomycin C (MMC) group, treated with MMC of routine dosage (B) and low-dosage (C) respectively; three SJZD groups, treated with SJZD of high (D), medium (E) and low-dosage (F) respectively; and two combined treatment groups, treated with SJZD of high-dosage + MMC of routine dosage(G) and SJZD of high-dosage + MMC of low-dosage(H). The medication was begun at 24 hrs after inoculation. The tumor inhibitory rate, activity of peritoneal macrophages after 14 days of treatment and change of peripheral white blood cells after 7 days of treatment were determined and the survival time of mice was observed. RESULTS: The survival time of mice in Group D was significantly higher than that in Group A (P < 0.05), while those in Group E and F showed insignificant difference as compared with those in Group A (P > 0.05). The highest tumor inhibitory rate was shown in Group B, but the survival time in that group showed no significant difference as compared to those in Group A (P > 0.05). The longest survival time (32.7 +/- 1.3 days) was shown in Group H, which was obviously different to that in other groups (P < 0.05). And the leukocyte counts and macrophage activity in Group H were better than those in Group B, C and G (P < 0.05), except that the tumor inhibitory rate was significantly lower than that in Group B, C and G (P < 0.05). CONCLUSION: Combined chemotherapy of SJZD with low dosage MMC has definite effect in inhibiting tumor growth in mice with bladder carcinoma, displaying special effects of toxicity attenuation and efficacy potentiation.

Antitumor effects of recombinant human interleukin-6 on mouse bladder carcinoma through Fas-mediated apoptosis.

PURPOSE: An apoptosis-inducing therapy is gradually becoming a new strategy for cancer treatment. The aim of this study was to investigate the mechanism of growth-inhibitory effects of recombinant human interleukin-6 (rhIL-6) on bladder tumor-bearing T739 mice in vivo. METHODS: Murine bladder transitional carcinoma cells (BTT739) were inoculated subcutaneously into T739 mice as a tumor model for evaluating the antitumor effects of rhIL-6. Then the mice were divided randomly into 5 groups: A, B, C, D and E. Different doses (0, 2, 4, 8 x 10(6) IU/kg body weight) of rhIL-6 were injected intraperitoneally twice per day and administered for 14 days, and 1 mg/kg/d mitomycin-C(MMC) was used as control. Tumor size was measured and determined as the mean of the largest diameter and the diameter at right angle. Animals were killed by CO(2) inhalation on the 15th day after tumor cell inoculation. Then, tumors were removed, weighed and collected. The tumor growth inhibition rate of rhIL-6 was calculated. The morphological characteristic changes of tumor cells were observed under electron microscope, and cell cycle analysis was determined by flow cytometry. The expressions of Fas, FasL and Bcl-2 protein on tumor cells were qualitatively detected by immunofluorescence cell staining, and their relative contents (rate of positive cells, RPC) were quantitatively determined with flow cytometry. RESULTS: rhIL-6 could inhibit bladder tumor growth in a dose-dependent manner in vivo. The tumor growth-inhibitory rates of 2, 4, 8 x 10(6) IU/kg rhIL-6 and 1 mg/kg MMC were 11.8, 39.5, 39.7 and 68.8%, respectively. Flow cytometry results showed that a hypodiploid peak before G1 phase could be found in tumor cells treated with rhIL-6. Moreover, the cells treated with rhIL-6 displayed disappearance of nucleoli, chromatin gathering under the nuclear membrane in mass or ring-shape under transmission electron microscopy. The rates of Fas, FasL protein-positive cells estimated by flow cytometry in rhIL-6-treated mice were (12.57 +/- 0.83) and (20.1 +/- 0.87) %, respectively, significantly higher than that (4.66 +/- 0.17) and (14.1 +/- 0.83) % in control mice (P < 0.01). There was no significant difference in the rate of Bcl-2 protein-positive cells between the mice in these two groups (P > 0.05). CONCLUSIONS: rhIL-6 had obvious antitumor effects on mouse bladder carcinoma in vivo, and the Fas signaling pathway might play an important role in rhIL-6-induced bladder carcinoma cell apoptosis.

[Changes and significance of peripheral blood count in tumor rejection induced by a low dose of melphalan in C57BL/6 mice].

AIM: To investigate the relationship between changes of peripheral blood counts and tumor rejection induced by a low dose of melphalan in C57BL/6 mice. METHODS: Mouse lymphoma EL4 cells were inoculated subcutaneously into wild type C57BL/6 mice. Twelve days later, 7.5 mg/kg melphalan were administered intraperitoneally and the same volume of Normal Saline as control. Tumor sizes were observed and recorded subsequently. Blood samples were obtained from orbital venous sinus on different days before and after melphalan treatment, and then complete blood counts were performed and the relationship between the alterations of blood counts and tumor shrinkage after melphalan treatment was analyzed. RESULTS: Tumor sizes decreased and tumors disappeared after 7.5 mg/kg melphalan treatment; while tumors grow continuously in control mice. The number of WBC was increased a little (10.6 + or - 2.3) x 10(9)/L 6 h after melphalan treatment, but there was no significant difference with mice before melphalan injection (9.8 + or - 0.32) x 10(9)/L (P>0.05); The number of WBC decreased significantly at 4(th) day after melphalan treatment (P<0.01); Later it increased a little, but at 28(th); day after melphalan it still obviously lower than that of the normal (P<0.01). Hemoglobin (Hb) concentration decreased from (132 + or - 7) g/L before melphalan treatment to (110 + or - 14) g/L at 6 h after melphalan treatment (P<0.05). Later, the amount of Hb was decreasing and at 7th day it got to its lowest point (96 + or - 5) g/L. It increased gradually back to normal in 2 weeks after melphalan treatment. The platelet count increased to (1502 + or - 142) x 10(9)/L 6 h after melphalan treatment, significantly higher that that (914 + or - 322) x 10(9)/L before melphalan injection (P<0.01). It maintained at a high level for one week and it recovered back to normal level at 28(th) day after melphalan treatment. CONCLUSION: Tumor shrinkage after melphalan treatment was not related to the decreased number of WBC or RBC, but correlated with the increased number of platelet in 10 days after melphalan treatment.

[The significance and function of IFN-gamma on the changes of peripheral blood platelet count during tumor-rejection induced by a low dose of melphalan in C57BL/6 mice].

AIM: To investigate the significance and function of IFN-gamma on the changes of peripheral blood platelet count during tumor-rejection induced by a low dose of melphalan in C57BL/6 mice. METHODS: Mouse tumor rejection model induced by a single dose of melphalan was used in this experiment. Different gene-type tumor-bearing mice (IFN-gamma(+/-) and IFN-gamma(-/-)), which had the same genetic background of C57BL/6, were treated intraperitoneally with melphalan (7.5 mg/kg). Tumor size was observed and recorded every one to three days in these different gene-type mice subsequently. Blood samples were obtained from orbital venous sinus on different days before and after melphalan treatment, and then complete blood counts were performed. The function of IFN-gamma on the efficacy of chemotherapy and the changes of blood platelet count in IFN-gamma(+/-) and IFN-gamma(-/-) mice after melphalan treatment was analyzed. RESULTS: There was no significant difference in tumor sizes and blood platelet count between IFN-gamma(-/-) and IFN-gamma(+/-) mice (P>0.05). On the first day after melphalan (7.5 mg/kg) treatment, there were no significant changes in tumor sizes between mice in these two groups (P>0.05). Tumors shrank a little in IFN-gamma(-/-) mice and then grew gradually. Tumors relapsed in 2 w after melphalan injection in all IFN-gamma(-/-) mice, while tumor volumes decreased progressively and tumor cured at last in IFN-gamma(+/-) mice. The number of blood PLT in IFN-gamma(+/-) mice increased to (1935+/-378) x 10(9)/L 6 h after melphalan treatment, significantly higher than before (P<0.01); While in IFN-gamma(-/-) mice it was (1183+/-186) x 10(9)/L 6 h after melphalan treatment, no obvious increase than before. There was significant difference in blood PLT 6 h after melphalan treatment between IFN-gamma(+/-) and IFN-gamma(-/-) mice (P<0.01). Later, the numbers of blood PLT in IFN-gamma(+/-) mice decreased gradually and it dropped to normal (1158+/-270) x 10(9)/L on 11th day after melphalan treatment (P>0.05); While it sustained in normal range in IFN-gamma(-/-) mice. There was no significant difference in blood platelet count between IFN-gamma(-/-) and IFN-gamma(+/-) mice. CONCLUSION: Peripheral blood platelet count increased on the first day after melphalan treatment and tumors cured in IFN-gamma(+/-) mice; While tumors relapsed and there is no increase in blood platelet count on the first day after melphalan treatment in IFN-gamma(-/-) mice. These data indicated that the increase of blood PLT count was related to the function of IFN-gamma in tumor-bearing mice in vivo during tumor rejection induced by a low dose of melphalan.

[Relationships between tumor shrinkage and peripheral blood cell changes during tumor-rejection induced by a high dose of 5-FU in C57BL/6 mice].

AIM: To investigate the relationship between the alterations of complete blood counts and tumor shrinkage during tumor rejection induced by a high dose of 5-FU in C57BL/6 mice. METHODS: Wild type C57BL/6 tumor-bearing mice were treated with different doses of 5-FU intraperitoneally. 75 mg/kg 5-FU was the minimal effective dose of 5-FU that could cure the tumor-bearing mice. Then another 6 tumor-bearing mice were treated intraperitoneally with 5-FU (75 mg/kg). Blood samples were obtained from orbital venous sinus on different days before and after 5-FU treatment, and then complete blood counts were performed and the relationship between the alterations of blood counts and tumor shrinkage after 5-FU treatment was analyzed. RESULTS: Tumor sizes decreased steadily and tumors disappeared within the first week after 5-FU treatment; and at the same time 75 mg/kg 5-FU also had side effects on peripherial blood cells. The number of WBC significantly decreased from the first day after 5-FU treatment (P<0.001). But during the 7 th to 15 th day the number of WBC rebounced back to normal level (P>0.05). Later it decreased again and it couldn't recover back to normal level at the 28th day after 5-FU treatment (P<0.01). The concentration of Hb decreased at the first day and lasted for 2 weeks (P<0.01). It increased gradually back to normal in 2 weeks after 5-FU treatment. The inhibitory effect of 5-FU on platelets count was not obvious. The platelet count increased significantly at the first and at the 11th day after 5-FU treatment respectively (P<0.01). CONCLUSION: Tumor shrinkage after 5-FU treatment is not related to the decreased number of WBC or RBC, but correlated with the increased number of platelet at the first day after 5-FU treatment.

[Changes and significance of peripheral blood platelet count in tumor shrinkage induced by a low dose of CTX in T739 mice].

AIM: To establish a mouse model for BTT739 tumor-bearing mice cured by a low dose of cyclophosphamide (CTX). And then to observe the dynamic changes and significance of peripheral blood counts especially blood platelet count during tumor shrinkage induced by a low dose of CTX in T739 mice. METHODS: Mouse bladder carcinoma tissues were inoculated subcutaneously into T739 mice. Seven days later, different doses of CTX or the same volume of NS were administered intraperitoneally to treat these tumor-bearing T739 mice. Tumor sizes were observed and recorded subsequently to find out the minimal dose of CTX that could cure most of these tumor-bearing mice. Then another 12 tumor-bearing mice were randomly divided into 15 mg/kg CTX treatment group and control group. Blood samples were obtained from orbital venous sinus on different times after CTX treatment. Complete blood counts were performed and the relationship between peripheral blood platelet counts and tumor shrinkage was analyzed. RESULTS: Within 2 weeks after CTX treatment, the speed of tumor shrinkage had a positive relationship with the dose of CTX used; but the survival rate of the tumor-bearing mice had a negative relationship with the dose of CTX used in 2 months after CTX treatment. 15 mg/kg CTX could cure most of the tumor bearing mice, while it had no remarkably inhibitive effects on peripheral blood cells. The perpherial platelet count increased to (1483.4+/-184.4)x10(9)/L in mice 6 h after CTX treatment. There was significant difference compared with that in mice of control group (1086.6+/-81.0)x10(9)/L (P<0.01). During the 2nd to 14th day after CTX treatment, there was no obvious difference in the platelet count between treatment group and control group (P>0.05). CONCLUSION: CTX 15 mg/kg could cure most of bladder tumor-bearing T739 mice. The transient increase of the peripheral platelet count in 6 h after CTX treatment may relate to the antitumor effects of CTX.

[Study of the immunological mechanism of anti-tumor effects of 5-FU by establishing EL4 tumor-bearing mouse models].

AIM: To investigate the immunological mechanism of anti-tumor effect of 5-FU by establishing lymphoma EL4 tumor-bearing mouse models in wild type C57BL/6 mice and nude C57BL/6 mice, respectively. METHODS: The mouse lymphoma EL4 cells were inoculated subcutaneously into wild type C57BL/6 mice (immune-competent mice). Twelve days later, 5-FU of different doses was administered intraperitoneally to treat these wild type C57BL/6 tumor-bearing mice. The size of tumors in the wild type C57BL/6 mice was observed and recorded to explore the minimal dose of 5-FU that could cure the tumor-bearing mice. Then the same amount of EL4 tumor cells was inoculated subcutaneously into wild type C57BL/6 mice and nude C57BL/6 mice (T cell-deficient mice) simultaneously, which had the same genetic background of C57BL/6. Twelve days later, 5-FU of the minimal dose was given intraperitoneally to treat both the wild type and nude C57BL/6 tumor-bearing mice. The size of tumors in the two different types of mice was observed and recorded. RESULTS: A single dose of 5-FU (75 mg/kg) cured both the EL4 tumor-bearing wild type C57BL/6 mice and the EL4 tumor-bearing nude C57BL/6 mice in the first week. Two weeks after 5-FU treatment, all of the nude mice died of tumor relapse while most of the wild type C57BL/6 mice were fully recovered. CONCLUSION: A single dose of 5-FU has marked anti-tumor effects on lymphoma EL4 tumor-bearing C57BL/6 mice with or without T lymphocytes. The relapse of tumors after 5-FU treatment might be related to the function of T lymphocytes.

[Relationship between TNFalpha and tumor rejection induced by a single dose of melphalan in C57BL/6 mice].

AIM: To investigate the relationship between TNFalpha and tumor rejection induced by a single dose of melphalan in C57BL/6 mice. METHODS: Different gene type mice (TNFR1(+/+), TNFR1(+/-) and TNFR1(-/-)) with the same genetic background of C57BL/6 were used in this experiment. Murine lymphoma EL4 cells were inoculated subcutaneously into the different gene type mice simultaneously. Twelve days later, 7.5 mg/kg melphalan was used intraperitoneally to treat the tumor-bearing mice with TNFR1(+/+), TNFR1(+/-) and TNFR1(-/-). The tumors in the different gene type mice were observed and recorded every one to three day. RESULTS: After the treatment of 7.5 mg/kg melphalan during the first week, the tumors in the different gene type mice shrank at a similar rate. In the following 2 months, the tumors in the TNFR1(+/+) and TNFR1(+/-) C57BL/6 mice gradually shrank and were cured but most tumors in the TNFR1(-/-) C57BL/6 mice relapsed after melphalan treatment. CONCLUSION: TNFalpha plays an important role in melphalan-induced tumor rejection. The anti-tumor effect of melphalan has no relationship with the expression of tumor necrosis factor 1 in tumor-bearing mice. TNFR1 is required to prevent or avoid the relapse of tumors in mice instead of tumor cells.

[Establishment of EL4 tumor-bearing mouse models and investigation on immunological mechanisms of anti-tumor effect of melphalan].

AIM: To establish mouse lymphoma EL4 tumor-bearing mouse models in wild type C57BL/6 mice and nude C57BL/6 mice respectively, and to further investigate the immunological mechanisms of anti-tumor effect of melphalan. METHODS: Mouse lymphoma EL4 cells were inoculated subcutaneously into wild type C57BL/6 mice (immune-competent mice). Twelve days later, melphalan of different doses were administered intraperitoneally to treat these wild type C57BL/6 tuomr-bearing mice. Tumor sizes were observed and recorded subsequently to find out the minimal dose of melphalan that could cure the tuomr-bearing mice. Then the same amount of EL4 tumor cells were inoculated subcutaneously into wild type C57BL/6 mice and nude C57BL/6 mice (T cell-deficient mice) simultaneously, which had the same genetic background of C57BL/6. Twelve days later, melphalan of the minimal dose was given intraperitoneally to treat both the wild type and nude C57BL/6 tuomr-bearing mice. Tumor sizes were observed and recorded in these two different types of mice subsequently. RESULTS: A single dose of melphalan (7.5 mg/kg) could cure EL4 tumor-bearing wild type C57BL/6 mice, but could not induce tumor regression in EL4 tumor-bearing nude C57BL/6 mice. CONCLUSION: A single dose of melphalan has obvious anti-tumor effect on mouse lymphoma EL4 tumor-bearing wild type C57BL/6mice, which requires the involvement of T lymphocytes in the host probably related to their killing functions.

[Relationship between anti-tumor effects of melphalan and IFN-gamma].

AIM: To investigate the relationship between IFN-gamma and anti-tumor effects of melphalan in vivo. METHODS: Different gene-type mice (IFN-gamma(+/+), IFN-gamma(+/-) and IFN-gamma(-/-)), which had the same genetic background of C57BL/6, were used in this experiment. Murine lymphoma EL4 cells were inoculated subcutaneously into different gene-type mice simultaneously. Twelve days later, 7.5 mg/kg melphalan was used intraperitoneally to treat all these IFN-gamma(+/+), IFN-gamma(+/-) and IFN-gamma(-/-) tumor-bearing mice. Tumor size was observed and recorded every one to three days in these different gene-type mice subsequently. RESULTS: After melphalan (7.5 mg/kg) treatment, tumor size decreased at a similar rate in IFN-gamma(-/-), IFN-gamma(+/-) and IFN-gamma(+/+) mice within the first 3 d. Tumors shrank further or completely disappeared in most of IFN-gamma(+/-) and IFN-gamma(+/+) mice, whereas tumors grew gradually in all IFN-gamma(-/-) mice. CONCLUSION: 7.5 mg/kg melphalan has obvious anti-tumor effects on tumor-bearing IFN-gamma(+/+) and IFN-gamma(+/-) mice, but little effects on IFN-gamma(-/-) mice. These data suggest that IFN-gamma is required for the anti-tumor effects of melphalan on tumor-bearing mice in vivo.