Oncogene expression is modulated by recombinant human interferon-beta in human breast-cancer cells

MiR-139 Induces an Interferon-β Response in Prostate Cancer Cells by Binding to RIG-1

BACKGROUND

We previously identified a panel of five miRNAs associated with prostate cancer recurrence and metastasis. Expression of one of the down-regulated miRNAs, miR-139-5p, was significantly associated with a lower incidence of biochemical recurrence and metastasis. Transcriptome profiling of miR-139-expressing prostate cancer cells revealed up-regulation of genes involved in interferon (IFN) stimulation. The association between miR-139 and IFN-β was further explored in this study.

MATERIALS AND METHODS

We examined miR-139 transfected PC3, Du145 and LNCaP cells and the associated IFN response by transcriptome sequencing, immunoblotting and pulldown assays.

RESULTS

Treatment of prostate cancer cells by miR-139 resulted in the up-regulation of IFN-related genes. Specifically, miR-139 induced expression of the IFN-β protein. The ability of miR-139 to induce IFN-β was due to its binding to RIG-1 and the induction of IFN-related genes was found to be dependent on RIG-1 expression.

CONCLUSION

miR-139 acts as an immune agonist of RIG-1 to enhance IFN-β response in prostate cancer cells.

Recombinant Human IFN-βAffects Androgen Receptor Level, Neuroendocrine Differentiation, Cell Adhesion, and Motility in Prostate Cancer Cells

We provide evidence that recombinant human interferon-beta (rHuIFN-beta) is able to increase androgen receptor (AR) expression, interfere with the acquisition of a neuroendocrine (NE) phenotype, and improve adhesion potential of androgen-insensitive prostate cancer cells (PC-3). The effect of rHuIFN-beta (10-1000 IU/mL) on AR, chromogranin A (CgA), E-cadherin (E-cad), N-cadherin (N-cad), and c-met levels was investigated by Western blotting after 48, 96, and 144 h. In agreement with our previous results, rHuIFN-beta (10-1000 IU/mL) induced a dramatic increase in AR (up to 5.3-fold, p < 0.001) that was already evident with the lowest cytokine concentration (10 IU/mL). A reduction in CgA levels (up to 45%, p < 0.002) was produced by 100 and 1000 IU/mL after 48-144 h. E-cad upregulation (up to 90%, p < 0.05) was observed starting from 96 h of treatment with 100 and 1000 IU/mL rHuIFN-beta and persisted until 144 h. An rHuIFN-beta-dependent reduction occurred in N-cad and c-met signal after a 48-96 h of treatment. This effect was particularly strong after 144 h of exposure to 1000 IU/mL rHuIFN-beta (81.5%, N-cad; 58%, c-met) (p < 0.002). Reverse transcription-PCR (RT-PCR) analysis of c-met expression demonstrated that the IFN-induced c-met downregulation mostly occurs at the transcriptional level (reduction up to nearly 50%, p < 0.000). Together, these results indicate that rHuIFN-beta may reduce the motility and invasiveness of poorly differentiated prostate cancer cells and interfere with the acquisition of an NE phenotype, often characterized by a low AR level.

Down regulation of major histocompatibility complex class I expression in mammary carcinoma of HER-2/neu transgenic mice

Transgenic mice carrying the HER-2/neu proto-oncogene under tissue-specific transcriptional control of a mammary tumor virus long terminal repeat (Tg-MMTVneu mice) spontaneously develop mammary carcinomas. HER-2/neu is a tumor antigen that can be recognized by cytotoxic T lymphocytes if tumor cells present the appropriate major histocompatibility complex (MHC) class I glycoproteins. The purpose of this work was to assess whether mammary carcinomas arising in Tg-MMTVneu mice correctly expressed MHC (H-2q) class I gene products. We analyzed by flow cytometry 51 primary tumors from 19 transgenic mice. About one-half of the tumors showed a reduced expression of class I antigens. All tumors were highly positive for membrane neu. Some mice had multiple mammary carcinomas with widely different MHC expression levels, and most mice had at least one tumor with a low expression. Treatment with gamma-interferon of carcinoma cells cultured in vitro induced a strong reexpression of H-2q antigens. Our results suggest that the immune response activated in vivo by HER-2/neu-positive tumors can lead to the emergence of escape variants characterized by a down-regulation of MHC class I products.

Advanced carcinoma of the pancreas: phase II study of combined chemotherapy, beta-interferon, and retinoids

Because of the poor response of pancreatic cancer to conventional therapy, the authors performed a phase II pilot study to evaluate whether beta-interferon and retinoids, added to active chemotherapeutic agents, could increase response rate and survival in a group of patients who had metastatic disease. Twenty-three chemotherapy-naive patients were treated as follows: epirubicin, 60 mg/m2, and mitomycin C, 10 mg/m2, intravenously on day 1; folinic acid, 200 mg/m2, and 5-fluorouracil (5-FU), 370 mg/m2, intravenously for 5 consecutive days. beta-Interferon, 1 x 10(6) IU/m2, subcutaneously three times a week, and retinol palmitate, 50,000 IU orally twice a day, were given between chemotherapy cycles. Patients having responses and disease stabilization were maintained with the same dose of beta-interferon and retinol palmitate. Treatment was given every 4 weeks for four courses or until onset of progression. A median of three courses of chemotherapy was delivered to each patient. All patients were evaluable. Eight patients responded (35%) and 8 (35%) had stable disease. Median time to progression and survival for all patients were, respectively, 6.1 months and 11 months. Toxicity was severe: 60% of patients had hematologic toxicity, 40% had gastrointestinal toxicity, 13% had cardiac toxicity, and 1 patient had a hemolitic-uremic syndrome. The combination of chemotherapy, beta-interferon, and retinoids shows activity in metastatic pancreatic carcinoma. Toxicity was high but patients who had responses and disease stabilization had prolonged symptom palliation.