Liang Zhuang

A new rat model of bone cancer pain produced by rat breast cancer cells implantation of the shaft of femur at the third trochanter level.

Bone cancer pain remains one of the most challenging cancer pains to fully control. In order to clarify bone cancer pain mechanisms and examine treatments, animal models mimicking the human condition are required. In our model of Walker 256 tumor cells implantation of the shaft of femur at the third trochanter level, the anatomical structure is relatively simple and the drilled hole is vertical and in the cortical bone only 1–2 mm in depth without injury of the distal femur. Pain behaviors and tumor growth were observed for 21 days. And neurochemical changes were further investigated in this model. The results showed that cancer-bearing rats demonstrated a decreased limb use score from day 14, an increased spontaneous flinching and guarding times from day 7 and a decreased withdrawal threshold from day 6. The tumor infiltration of bone was monitored by MRI and further verified by histological examination. C-fos and the capsaicin receptor (TRPV1) positive neurons were more expressed in cancer-bearing rats and the substance P expression has no difference, suggesting that neurons were activated in the model. Our animal model demonstrated time-dependent tumor growth and pain behaviors and will be a novel animal model of bone cancer pain in the future.

Pregabalin attenuates docetaxel-induced neuropathy in rats

Chemotherapy-induced neuropathy is a serious clinical problem for patients receiving cancer treatment. The aim of this study was to investigate the potential efficacy of pregabalin in chemotherapy-induced neuropathy in rats. A total of 35 male Sprague-Dawley rats were randomly divided into 5 groups: group 1, naive control; group 2, treated with pregabalin (30 mg/kg p.o., for 8 days); group 3, docetaxel was given by single intravenous infusion at 10 mg/kg; groups 4 and 5, pregabalin at 10 mg/kg and 30 mg/kg respectively was orally administered for 8 days after the docetaxel treatment. On day 8, behavioral test was performed, and substance P and CGRP release in dorsal root ganglion (DRG) and sciatic nerve were analyzed by electron microscope. Our results showed that docetaxel induced mechanical allodynia, mechanical hyperalgesia, heat hypoalgesia, cold allodynia, and sciatic nerve impairment and substance P and CGRP release in DRG. However, oral administration of pregabalin (10 mg/kg and 30 mg/kg) for 8 consecutive days significantly attenuated docetaxel-induced neuropathy by ameliorating heat hypoalgesia, cold allodynia, impairment of sciatic nerve and reducing the release of substance P and CGRP. The findings in the present study reveal that pregabalin may be a potential treatment agent against chemotherapy-induced neuropathy.SummaryChemotherapy-induced neuropathy is a serious clinical problem for patients receiving cancer treatment. The aim of this study was to investigate the potential efficacy of pregabalin in chemotherapy-induced neuropathy in rats. A total of 35 male Sprague-Dawley rats were randomly divided into 5 groups: group 1, naive control; group 2, treated with pregabalin (30 mg/kg p.o., for 8 days); group 3, docetaxel was given by single intravenous infusion at 10 mg/kg; groups 4 and 5, pregabalin at 10 mg/kg and 30 mg/kg respectively was orally administered for 8 days after the docetaxel treatment. On day 8, behavioral test was performed, and substance P and CGRP release in dorsal root ganglion (DRG) and sciatic nerve were analyzed by electron microscope. Our results showed that docetaxel induced mechanical allodynia, mechanical hyperalgesia, heat hypoalgesia, cold allodynia, and sciatic nerve impairment and substance P and CGRP release in DRG. However, oral administration of pregabalin (10 mg/kg and 30 mg/kg) for 8 consecutive days significantly attenuated docetaxel-induced neuropathy by ameliorating heat hypoalgesia, cold allodynia, impairment of sciatic nerve and reducing the release of substance P and CGRP. The findings in the present study reveal that pregabalin may be a potential treatment agent against chemotherapy-induced neuropathy.

Association between symptoms and their severity with survival time in hospitalized patients with far advanced cancer

Objective: To assess the significance of symptoms and their severity for predicting survival of hospitalized patients with far advanced cancer. Methods: Two hundred fifty-six patients with far advanced cancer at the Cancer Center of Tongji Hospital, China were assessed by the Chinese version of the M.D. Anderson Symptom Inventory (MDASI-C). A Cox regression model was used to determine symptoms that could predict survival time. The log-rank test was used to compare the survival of patients accompanied by significant symptoms at different intensities. Results: Median survival was 49 days. Fatigue was the most common and severe symptom, followed by lack of appetite, disturbed sleep, and pain. Multivariate analysis showed that fatigue, shortness of breath, lack of appetite, and feeling sad were independent prognostic factors for survival time (p < 0.05), with a hazard ratio of dying of 1.39, 1.13, 1.33, and 1.16, respectively. The survival time for patients with different intensities of the four symptoms showed significant differences (p < 0.01). Conclusions: Fatigue, lack of appetite, feeling sad, and shortness of breath could be predictive factors for survival time of hospitalized patients with far advanced cancer. The more severe these symptoms are, the shorter will be survival time.

Changes of survivin mRNA and protein expression during paclitaxel treatment in breast cancer cells.

In order to investigate the role of antiapoptosis gene, survivin in the resistance to palcitaxel, the expression of survivin mRNA and protein in the process of paclitaxel treatment in breast cancer cell line MCF-7 was detected MCF-7 cells were incubated with paclitaxel at different concentrations. The growth inhibition rate of MCF-7 was investigated by tetrazolium bromide (MTT) colorimetry. The change of apoptosis was detected by Annexin-V/PI methods. The changes in the expression of survivin mRNA and protein were studied by reverse transcription polymerase chain reaction (RT-PCR) and Western-blot assay respectively. The growth inhibition rate of MCF-7 was increased in a concentration-and time-dependent manner. Paclitaxel of higher concentration could effectively induce apoptosis in MCF-7 cells after 48 h, while the expression of survivin was increased at early time (within 6 h) and decreased after 24 h regardless of treatment concentrations of paclitaxel. It suggested that tumor cells might evade the paclitaxel-induced cell cycle arrest and apoptosis by increasing the level of survivin at early treatment time.

Induction of ERBB2 nuclear transport after radiation in breast cancer cells.

SummaryThe ERBB2 nuclear transport in breast cancer cell lines after radiation and its possible role in radiation tolerance were observed. Confocal microscopy and Western blotting were applied to detect the nuclear ERBB2 expression after radiation in breast carcinomas cells. And the effects of Herceptin, AG825 and Cisplatin on the expression of nuclear ERBB2 were investigated. Survival fractions were also observed. After radiation, compared with control group, confocal microscopy and Western blot revealed that the expression of nuclear ERBB2 was increased in breast cancer cells time-dependently. Herceptin, and AG825 could significantly inhibit the radiation-induced nuclear ERBB2 expression, and decrease survival fractions. Cisplatin also induced the nuclear ERBB2 expression in breast cancer cells with high ERBB2 expression. It was concluded that radiation could induce ERBB2 nuclear transport, and nuclear ERBB2 may correlate with radiation resistance in breast cancer cells with high ERBB2 expression.The ERBB2 nuclear transport in breast cancer cell lines after radiation and its possible role in radiation tolerance were observed. Confocal microscopy and Western blotting were applied to detect the nuclear ERBB2 expression after radiation in breast carcinomas cells. And the effects of Herceptin, AG825 and Cisplatin on the expression of nuclear ERBB2 were investigated. Survival fractions were also observed. After radiation, compared with control group, confocal microscopy and Western blot revealed that the expression of nuclear ERBB2 was increased in breast cancer cells time-dependently. Herceptin, and AG825 could significantly inhibit the radiation-induced nuclear ERBB2 expression, and decrease survival fractions. Cisplatin also induced the nuclear ERBB2 expression in breast cancer cells with high ERBB2 expression. It was concluded that radiation could induce ERBB2 nuclear transport, and nuclear ERBB2 may correlate with radiation resistance in breast cancer cells with high ERBB2 expression.

Effects of 5-Aza-CdR on the proliferation of human breast cancer cell line MCF-7 and on the expression of Apaf-1 gene

SummaryHypermethylation in the promoter region of tumor suppressor genes is a common mechanism of gene silencing, which tends to occur in cancer. The effects of 5-Aza-2′-deoxycytidine (5-Aza-CdR), a specific DNA methyltransferase inhibitor, on the cell proliferation of human breast cancer cell line MCF-7 and on the expression of Apaf-1 gene were investigated. Human MCF-7 cells were incubated with increasing concentrations of 5-Aza-CdR for 12 to 120 h. The growth inhibition rates of MCF-7 cells were detected by MTT assay. Changes of cell cycle distribution and apoptotic rates of MCF-7 cells were determined by flow cytometry. The expressions of DNA methyltransferase 3b mRNA and Apaf-1 mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Meanwhile, the expression of Apaf-1 protein was detected by Western blotting. The results showed that 5-Aza-CdR significantly inhibited the growth of MCF-7 cells and the growth inhibition rate of MCF-7 cells was significantly enhanced with the concentration of 5-Aza-CdR and the action time. Flow cytometry indicated that 5-Aza-CdR could significantly induce G1/S cell cycle arrest and increase the apoptosis rate of MCF-7 cells. The mRNA and protein expressions of Apaf-1 were up-regulated in MCF-7 cells treated with 5-Aza-CdR, which was accompanied by down-regulation of DNA methyltransferase 3b mRNA. It is concluded that 5-Aza-CdR might retard the growth of tumor cells and promote the apoptosis of MCF-7 breast cancer cells by inhibiting the expression of DNA methyltransferase 3b and re-activating the Apaf-1 gene expression.Hypermethylation in the promoter region of tumor suppressor genes is a common mechanism of gene silencing, which tends to occur in cancer. The effects of 5-Aza-2′-deoxycytidine (5-Aza-CdR), a specific DNA methyltransferase inhibitor, on the cell proliferation of human breast cancer cell line MCF-7 and on the expression of Apaf-1 gene were investigated. Human MCF-7 cells were incubated with increasing concentrations of 5-Aza-CdR for 12 to 120 h. The growth inhibition rates of MCF-7 cells were detected by MTT assay. Changes of cell cycle distribution and apoptotic rates of MCF-7 cells were determined by flow cytometry. The expressions of DNA methyltransferase 3b mRNA and Apaf-1 mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Meanwhile, the expression of Apaf-1 protein was detected by Western blotting. The results showed that 5-Aza-CdR significantly inhibited the growth of MCF-7 cells and the growth inhibition rate of MCF-7 cells was significantly enhanced with the concentration of 5-Aza-CdR and the action time. Flow cytometry indicated that 5-Aza-CdR could significantly induce G1/S cell cycle arrest and increase the apoptosis rate of MCF-7 cells. The mRNA and protein expressions of Apaf-1 were up-regulated in MCF-7 cells treated with 5-Aza-CdR, which was accompanied by down-regulation of DNA methyltransferase 3b mRNA. It is concluded that 5-Aza-CdR might retard the growth of tumor cells and promote the apoptosis of MCF-7 breast cancer cells by inhibiting the expression of DNA methyltransferase 3b and re-activating the Apaf-1 gene expression.

Caveolin-1 is involved in radiation-induced ERBB2 nuclear transport in breast cancer cells

SummaryThis study examined the radiation-induced ERBB2 nuclear transport in the BT474 breast cancer cell line and the relationship between caveolin-1 and radiation-induced ERBB2 nuclear transport. The BT474 cells were treated with herceptin (200 nmol/L), PP2 (a caveolin-1 inhibitor, 100 nmol/L) and irradiation combined or alone. Confocal microscopy was used to observe the nuclear import of ERBB2 and caveolin-1 after irradiation. Western blotting was employed to detect the expression of ERBB2, caveolin-1 and DNA-PKcs after irradiation, and immunoprecipitation to identify the ERBB2 and caveolin-1 complex before perinuclear ERBB2 localization. Confocal microscopy showed the transport of ERBB2 and caveolin-1 from the cell membrane to the nucleus 15 min after irradiation and the proteins accumulated at the perinuclear region within 45 min. Western blotting revealed that the expression levels of ERBB2, caveolin-1 and DNA-PKcs were increased after irradiation and reached a peak 45 min later. Both herceptin and PP2 treatments were found to decrease ERBB2 expression. An immune complex composed of ERBB2 and caveolin-1 was found in the herceptin group after irradiation. It was concluded that after irradiation, ERBB2 may be transported from the cell membrane to the nucleus and activate DNA-PKcs to trigger DNA double-strand break (DSB) repair; caveolin-1 may participate in this process. Treatments involving the downregulation of caveolin-1 may increase the radiosensitization of breast cancer cells.This study examined the radiation-induced ERBB2 nuclear transport in the BT474 breast cancer cell line and the relationship between caveolin-1 and radiation-induced ERBB2 nuclear transport. The BT474 cells were treated with herceptin (200 nmol/L), PP2 (a caveolin-1 inhibitor, 100 nmol/L) and irradiation combined or alone. Confocal microscopy was used to observe the nuclear import of ERBB2 and caveolin-1 after irradiation. Western blotting was employed to detect the expression of ERBB2, caveolin-1 and DNA-PKcs after irradiation, and immunoprecipitation to identify the ERBB2 and caveolin-1 complex before perinuclear ERBB2 localization. Confocal microscopy showed the transport of ERBB2 and caveolin-1 from the cell membrane to the nucleus 15 min after irradiation and the proteins accumulated at the perinuclear region within 45 min. Western blotting revealed that the expression levels of ERBB2, caveolin-1 and DNA-PKcs were increased after irradiation and reached a peak 45 min later. Both herceptin and PP2 treatments were found to decrease ERBB2 expression. An immune complex composed of ERBB2 and caveolin-1 was found in the herceptin group after irradiation. It was concluded that after irradiation, ERBB2 may be transported from the cell membrane to the nucleus and activate DNA-PKcs to trigger DNA double-strand break (DSB) repair; caveolin-1 may participate in this process. Treatments involving the downregulation of caveolin-1 may increase the radiosensitization of breast cancer cells.