Carbenoxolone enhances inhibitory effect of RSL3 against cisplatin-resistant testicular cancer cells by promoting ferroptosis / 南方医科大学学报

OBJECTIVE@#To investigate the inhibitory effect of RSL3 on the proliferation, invasion and migration of cisplatinresistant testicular cancer cells (I-10/DDP) and the effect of carbenoxolone on the activity of RSL3 against testicular cancer.@*METHODS@#MTT assay was used to evaluate the survival rate of I-10/DDP cells following treatment with RSL3 (1, 2, 4, 8, 16 or 32 μmol/L) alone or in combination with carbenoxolone (100 μmol/L) or after treatment with Fer-1 (2 μmol/L), RSL3 (4 μmol/L), RSL3+Fer-1, RSL3+carbenoxolone (100 μmol/L), or RSL3+Fer-1+carbenoxolone. Colony formation assay was used to assess the proliferation ability of the treated cells; wounding-healing assay and Transwell assay were used to assess the invasion and migration ability of the cells. The expression of GPX4 was detected using Western blotting, the levels of lipid ROS were detected using C11 BODIPY 581/591 fluorescent probe, and the levels of Fe2+ were determined with FerroOrange fluorescent probe.@*RESULTS@#RSL3 dose-dependently decreased the survival rate of I-10/DDP cells, and the combined treatment with 2, 4, or 8 μmol/L RSL3 with carbenoxolone, as compared with RSL3 treatment alone, resulted in significant reduction of the cell survival rate. The combination with carbenoxolone significantly enhanced the inhibitory effect of RSL3 on colony formation, wound healing rate (P=0.005), invasion and migration of the cells (P < 0.001). Fer-1 obviously attenuated the inhibitory effects of RSL3 alone and its combination with carbenoxolone on I-10/DDP cells (P < 0.01). RSL3 treatment significantly decreased GPX4 expression (P=0.001) and increased lipid ROS level (P=0.001) and Fe2+ level in the cells, and these effects were further enhanced by the combined treatment with carbenoxolone (P < 0.01).@*CONCLUSION@#Carbenoxolone enhances the inhibitory effect of RSL3 on the proliferation, invasion and migration of cisplatin-resistant testicular cancer cells by promoting RSL3-induced ferroptosis.

Dexmedetomidine attenuates ferroptosis through regulation of Nrf2 on HT22 cells with hypoxia/reoxyge nation / 中国药理学通报

Aim To investigate the effects of Dexmedetomidine(DEX)on HT22 cells with hypoxia/reoxygenation based on ferroptosis and the underlying mechanism.Methods HT22 cells were used to prepare H/R injury model.In order to investigate the optimal concentration of DEX, cells were divided into five groups: control group, H/R group, low concentration(H/R+DEX2.5, 2.5 μmol·L-1), medium concentration(H/R+DEX5, 5 μmol·L-1), high concentration(H/R+DEX10, 10 μmol·L-1)DEX intervention H/R group, and the survival rates of cells were detected by MTT assay.To investigate the mechanism of the protective effects on HT22 cells with H/R injury, HT22 cells were divided into four groups: control group, H/R group, H/R+DEX5 group, and H/R+DEX5 +ML385 group.The survival rates of cells were detected by MTT assay; the levels of Fe2+ were detected by FerroOrange fluorescent probe; the C11BODIPY581/591 was used to detect the change of lipid ROS on the cells; MDA and reduced glutathione kits were used to detect the content of MDA and GSH of cells respectively.The expressions of Nrf2, GPX4, TFR1 and SLC7A11 were detected by Western blot.Results Compared with control group, the survival rate of cells, the content of GSH, and the expression of Nrf2, GPX4 and SLC7A11 all significantly decreased(all P<0.05), the level of lipid ROS, the content of MDA, the level of Fe2+, and the expression of TFR1 all significantly increased in H/R group(all P<0.01).Compared with H/R group, the survival rate of cells, the content of GSH, and the expression of Nrf2, GPX4 and SLC7A11 significantly increased(all P<0.05), the level of lipid ROS, the content of MDA, the level of Fe2+, and the expression of TFR1 significantly decreased with the treatment of DEX(all P<0.05).Compared with H/R+DEX group, the survival rate of cells, the content of GSH, and the expression of Nrf2, GPX4 and SLC7A11 markedly decreased(all P<0.05), the lipid ROS, MDA and Fe2+, and the expression of TFR1 significantly increased in H/R+DEX+ML385 group(all P<0.05).Conclusions DEX can reduce H/R injury on HT22 cells by inhibiting ferroptosis, and the mechanism might be related to the promotive expression of Nrf2.

Role of pannexin 1 channels in cisplatin-induced apoptosis in I-10 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of pannexin 1 channels in cisplatin-induced apoptosis in I-10 cells and the mechanisms.</p><p><b>METHODS</b>MTT assay was used to assess the cytotoxicity of cisplatin (DDP) in I-10 cells. Annexin V/PI double staining and Hoechst 33258 fluorescence staining were employed to detect early- and late-stage apoptosis of the cells, respectively. Extracellular ATP level and intracellular IP3 level in the cells were detected using commercial detection kits.</p><p><b>RESULTS</b>I-10 cells exposed to both CBX (a pannexin 1 channel inhibitor) and DDP showed a higher cell viability compared with the cells exposed to DDP alone (P<0.01). CBX significantly decreased cisplatin-induced early-stage apoptosis (P<0.001) and late-stage apoptosis (P<0.01), and cause obvious reductions in extracellular ATP and intracellular IP3 levels during cisplatin-induced apoptosis (P<0.05).</p><p><b>CONCLUSION</b>Pannexin 1 channels participate in cisplatin-induced apoptosis in I-10 cells possibly through the ATP/IP3 pathway.</p>

Gefitineb inhibits the growth and induces the apoptosis of mouse I-10 Leydig testicular cancer cells in vitro / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the inhibitory effect of gefitineb on the proliferation and its inducing effect on the apoptosis of mouse I-10 Leydig testicular cancer cells in vitro.</p><p><b>METHODS</b>We treated I-10 Leydig testicular cancer cells of mice with gefitineb at 0, 1.25, 2.5, 5, 10, 20, and 40 µmol/L. Then we determined the inhibitory effect of gefitineb on the growth of the cells by MTT, detected their early and late apoptosis by Annexin V-FITC/propidium iodide double staining and Hoechst 33258 nuclear staining, respectively, and observed the expressions of apoptosis-related proteins Bcl-2, Bax and caspase 3/9 by Western blot.</p><p><b>RESULTS</b>Compared with the blank control group, gefitineb significantly inhibited the proliferation of the I-10 cells at 10 and 20 µmol/L (P < 0.05). The survival rate of the cells was (32.4 ± 2.8)% (P < 0.01) and their early and late apoptosis rates were (26.7 ± 4.2)% and (59.33 ± 10.2)% in the 40 µmol/L group, significantly different from those in the control (P < 0.05 and P <0.01). In comparison with the blank control group, gefitineb at 10, 20, and 40 µmol/L increased the expression of pro-apoptotic protein Bax by (41.9 ± 7.1), (60.1 ± 9.8), and (69.0 ± 11.3)% (all P < 0.05), decreased that of apoptosis-inhibitory protein Bcl-2 by (50.3 ± 8.9), (63.9 ± 6.9), and (88.7 ± 13.9)% (all P < 0.05), and elevated that of the cleft proteins caspase-3 by (69.0 ± 6.9)% (P < 0.05), (71.5 ± 8.1)% (P < 0.05), and (110.9 ± 14.2)% (P < 0.01) and caspase-9 by (51.8 ± 4.9), (54.7 ± 6.7), and (43.8 ± 11.8)% (all P < 0.05).</p><p><b>CONCLUSION</b>Gefitineb can increase the cytotoxicity of I-10 Leydig testicular cancer cells of mice and induce their apoptosis via the mitochondria-mediated apoptosis signaling pathway.</p>

Baicalein enhances the gap junction in the TM4 Sertoli cells of mice / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effect of baicalein on the gap junction intercellular communication (GJIC) in the TM4 Sertoli cells of the mouse testis and its related mechanism.</p><p><b>METHODS</b>We measured the cytotoxicity of different concentrations of baicalein on the TM4 Sertoli cells in the mouse testis by MTT, detected the fluorescence transfer of the TM4 Sertoli cells by parachute assay, and determined the expression of the protein connexin 43 ( Cx43) in the baicalein-treated cells by Western blot and immunofluorescence assay.</p><p><b>RESULTS</b>Baicalein produced no obvious cytotoxicity on the TM4 Sertoli cells at the concentration below 60 µmol/L but significantly increased their GJIC at 0-20 µmol/L (P < 0.01). Western blot and immunofluorescence assay showed that 0-20 µmol/L baicalein remarkably elevated the expression of Cx43 in the TM4 cells (P < 0.01) and on the membrane of the TM4 cells.</p><p><b>CONCLUSION</b>Baicalein at the concentration of 0-20 µmol/L can significantly enhance GJIC in mouse TM4 Sertoli cells by increasing the expression of the Cx43 protein.</p>

Inhibition of gap junctional intercellular communication protects astrocytes from hypoxia/reoxygenation injury / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of inhibiting gap junctional intercellular communication on hypoxia/reoxygenation injury in astrocytes.</p><p><b>METHODS</b>Primary cultured cerebral cortical astrocytes of neonate rats were divided into normal control group, hypoxia reoxygenation injury group and 18-α-glycyrrhetinic acid and oleamide (gap junctional intercellular channel inhibitors) group. The gap junction intercellular communication was determined by Parachute assay. The viability of astrocyes was detected by MTT assay. The apoptosis of astrocytes were detected with annexin V/PI and Hoechst 33258 staining.</p><p><b>RESULTS</b>Compared with the normal control group, the gap junctional function of astrocytes was increased significantly in ischemia/reperfusion group (P<0.01), the surviving fraction of astrocytes decreased significantly (P<0.01) and its cell apoptosis ratio increased significantly (P<0.01). Compared with the ischemia/reperfusion group, the gap junctional function of astrocytes in18-α-glycyrrhetinic acid and oleamide group decreased significantly (P<0.01), the viability of astrocytes increased significantly (P<0.01), while cell apoptosis decreased significantly (P<0.01).</p><p><b>CONCLUSION</b>Inhibition of intercellular gap junction has protective effect against hypoxia/reoxygenation injury in astrocytes.</p>

Sodium valproate enhances doxorubicin cytotoxicity in breast cancer cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of sodium valproate, a histone deacetylase inhibitor, on the cytotoxicity of doxorubicin in breast cancer cells.</p><p><b>METHODS</b>Western blotting was used to assess Cx43 protein expression in breast cancer Hs578T cells exposed to doxorubicin and sodium valproate. MTT assay was used to determine the cytotoxicity of doxorubicin; annexin V/PI double staining and Hochest 33258 fluorescence staining were employed to detect doxorubicin-induced early and late apoptosis, respectively.</p><p><b>RESULTS</b>Western blotting showed that sodium valproate significantly increased Cx43 protein expression in Hs578T cells (P/0.01). The cells exposed to both sodium valproate and doxorubicin showed significantly lowered cell viability compared with the cells exposed to doxorubicin alone (P/0.01). Exposure to both sodium valproate and doxorubicin resulted in significantly increased early and late cell apoptosis rate compared with doxorubicin treatment alone (P/0.01).</p><p><b>CONCLUSION</b>sodium valproate can significantly enhance the cytotoxicity of doxorubicin and increase doxorubicin-induced apoptosis in breast cancer cells in vitro possibly by enhancing the gap junction function.</p>

Total flavonoids of litsea coreana decreases the cytotoxicity of oxaliplatin in TM3 Leydig cells via enhancing the function of gap junction / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effects of total flavonoids of Litsea Coreana (TFLC) on the gap junction (GJ) intercellular communication in TM3 testicular Leydig cells and whether TFLC can reduce the cytotoxicity of oxaliplatin (OHP) in vitro.</p><p><b>METHODS</b>We detected the effect of TFLC on the dye spread of the in vitro cultured TM3 cells by parachute assay, observed changes in the expression of connexin 43 (Cx43) total protein in the TFLC-treated TM3 cells by Western blot, and determined the effects of TFLC on the expression of Cx43 on the membrane of the TM3 cells by immunofluorescence assay and on the cytotoxicity of OHP by MTT assay.</p><p><b>RESULTS</b>TFLC obviously enhanced the GJ function with the increasing of the TFLC concentration in the TM3 cells. Western blot and immunofluorescence assay confirmed that TFLC significantly enhanced the expression of Cx43 total protein and Cx43 expression on the membrane of the TM3 cells. MTT assay showed that at a high cell density (confluent with GJ formation), 20 microg/ml TFLC enhanced the GJ function of the TM3 cells and reduced the cytotoxicity of OHP (P < 0.05), while at a low density (preconfluent with no GJ formation), TFLC exhibited no effect on the cytotoxicity of OHP (P > 0.05).</p><p><b>CONCLUSION</b>TFLC increases the Cx43 expression and GJ function in normal TM3 Leydig cells, and the enhancement of GJ function reduces the cytotoxicity of OHP.</p>

PP2 enhances intercellular communication of gap junction in breast cancer Hs578T cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effect of Src kinase inhibitor PP2 on intercellular communication of gap junction in breast cancer cells.</p><p><b>METHODS</b>Cultured breast cancer Hs578T cells were treated with various concentrations of pp2 (0,1,2,4,8,16,32 μmol/L) for 24h. Cell growth was determined by MTT assay; dye spread in Hs578T cells was measured by Parachute assay; and the expression of Src kinase in Hs578T cells was detected by Western blot.</p><p><b>RESULTS</b>MTT assay showed that the survive rate of Hs578T cells treated with PP2 (1 ≊ 8 μmol/L) was 98% ± 3% ≊ 94 % ± 4%. Parachute assay showed that compared to control group the standard normalized dye spread rates of Hs578T cells treated with 1,2,4 and 8 μmol/L PP2 were 1.60 ± 0.08,2.00 ± 0.05,2.20 ± 0.05 and 2.70 ± 0.09,respectively (all P<0.01). Moreover,compared to control group at the same time points,the standard normalized dye spread of Hs578T cells treated with 8 μmol/L PP2 for 6,12 and 24 h were 1.4 ± 0.05,1.7 ± 0.06,and 2.2 ± 0.07,respectively (all P<0.01). Western blot showed that the expression ratios of Src kinase/β-actin of Hs578T cells treated with 1,2,4 and 8 μmol/L PP2 for 24 h were 0.93 ± 0.02,0.70 ± 0.09,0.66 ± 0.09 and 0.36 ± 0.10,which were significantly inhibited compared with control group (P<0.05 or 0.01). And the expression ratio of Src kinase/β-actin of Hs578T cells treated with 8 μmol/L PP2 for 6,12 and 24h was 0.82 ± 0.03,0.66 ± 0.08 and 0.59 ±0.09, which were all inhibited significantly compared to control group (P<0.01).</p><p><b>CONCLUSION</b>PP2 enhances the gap junction function in breast cancer Hs578T cells, which is probably related to the inhibition of Src kinase.</p>

Influence of Cx26/Cx32 gap junction channel on antineoplastic effect of etoposide in Hela cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the influence of Cx26/Cx32 gap junction channel on the antineoplastic effect of etoposide in Hela cervical cancer cells.</p><p><b>METHODS</b>Fluorescence trace was used to assay the gap junction intercellular communication mediated by Cx26/Cx32 in Hela cells and its functional modulation by the pharmacological agents (oleamide, retinoid acid). A standard colony-forming assay was applied to determine the cell growth-inhibiting effect of etoposide in Hela cells with functional modulation of the gap junction. Hoechst 33258 staining was used to assess the changes in etoposide-induced apoptosis of Hela cells with altered gap junction functions.</p><p><b>RESULTS</b>Oleamide markedly decreased while retinoid acid obviously increased the gap junction function in Hela cells. Standard colony-forming assay showed that etoposide produced a lowered antiproliferative effect in Hela cells with reduced gap junction and an increased antiproliferative effect in cells with enhanced gap junction function. In cells with a reduced gap junction function, etoposide induced a lowered apoptosis rate, which increased obviously in cells with an enhanced gap junction function.</p><p><b>CONCLUSION</b>The antineoplastic effect of etoposide is reduced in Hela cells with a decreased gap junction intercellular communication mediated by Cx26/Cx32 and is enhanced in cells with an increased gap junction intercellular communication.</p>