Type I interferons in the treatment of pancreatic cancer: mechanisms of action and role of related receptors

DTNQ-Pro, a Mimetic Dipeptide, Sensitizes Human Colon Cancer Cells to 5-Fluorouracil Treatment

The resistance of growing human colon cancer cells to chemotherapy agents has been correlated to endogenous overexpression of stress proteins including the family of heat shock proteins (HSPs). Previously, we have demonstrated that a quinone-based mimetic dipeptide, named DTNQ-Pro, induced differentiation of growing Caco-2 cells through inhibition of HSP70 and HSP90. In addition, our product induced a HSP27 and vimentin intracellular redistribution. In the present study, we have evaluated whether a decrease of stress proteins induced by DTNQ-Pro in Caco-2 cells could sensitize these cells to treatment with 5-fluorouracil (5-FU) cytotoxicity. The pretreatment of Caco-2 with 500 nM of DTNQ-Pro increases lipid peroxidation and decreases expression of p38 mitogen-activated protein kinase (MAPK) and FOXO3a. At the same experimental conditions, an increase of the 5-FU-induced growth inhibition of Caco-2 cells was recorded. These effects could be due to enhanced DTNQ-Pro-induced membrane lipid peroxidation that, in turn, causes the sensitization of cancer cells to the cytotoxicity mediated by 5-FU.

Everolimus is an active agent in medullary thyroid cancer: a clinical and in vitro study

Everolimus, an mTOR inhibitor, which has been demonstrated to induce anti-tumour effects in different types of neuroendocrine tumours, has never been evaluated in patients with medullary thyroid cancer (MTC). The aim of this study was to evaluate the in vitro and in vivo effects of everolimus in combination with octreotide in MTC. Two patients with progressive metastatic MTC and high calcitonin levels were treated with everolimus 5–10 mg/day. Both patients were under treatment with octreotide LAR at the study entry. An in vitro study was also performed to assess everolimus effects on MTC cell lines (TT and MZ-CRC-1 cells). A tumour response was observed in both patients. Serum calcitonin decreased by 86% in patient 1 and by 42% in patient 2. In TT and MZ-CRC-1 cells, everolimus induced a significant dose-dependent inhibition in cell proliferation. This effect seems to be related to a cell cycle arrest in G₀/G₁ phase in both cell lines and to the induction of cellular senescence in TT cells. Everolimus in combination with octreotide may be active as anti-tumour therapy in patients with progressive metastatic MTC, suggesting to further evaluate this agent in MTC patients in a large prospective study.

pEGFR-Tyr 845 expression as prognostic factors in oral squamous cell carcinoma: a tissue-microarray study with clinic-pathological correlations

The EGFR (epidermal growth factor receptor) a member of the family of transmembrane protein kinase receptors known as the erbB family shows a significant correlation with the presence of metastases and poorly differentiated oral cancer. Aim of the present work is to define the key-role of EGFR in oral cancer prognosis. We have analyzed the EGFR expression on 149 cases of oral squamous cell cancers (OSCC) and we have found that it was poorly expressed in normal oral epithelium, but its expression was significantly increased in OSCCs. Moreover, we have recorded that both pEGFR-Tyr 845 and pEGFR-Tyr 1068 were mainly distributed in high histological grading and in advanced stages. Western blotting has confirmed the total absence of EGFR phosphorylation in normal oral epithelium and the higher level of protein phosphorylation in representative cases of OSCCs. The EGF-R amplification was found by fluorescence in situ hybridization (FISH) in 14% of OSCC; interestingly, EGF-R amplification was mainly observed in OSCC with higher histological grading (G2 and G3) and advanced stage (pT4) sub-groups. Kaplan-Meyer survival analysis suggested that patients with positive pEGFR-Tyr 845 tumors had a worse prognosis and were bad responders to chemotherapy. These results confirm the central role of EGF-R activation status as a prognostic biomarker in OSCC.

The expression of interferon receptor α/β in human pancreatic cancer in nude mice is essential for tumor response to interferon α treatment

BACKGROUND

Adjuvant interferon based chemoradiation has rendered promising results against pancreatic cancer. This study evaluated the in vivo effect of interferon α on two human pancreatic carcinoma cell lines implanted in nude.

MATERIAL AND METHODS

MiaPaCa-2 expressed the interferon α/β receptor and Panc-1 cells did not. Regimen I consisted of intraperitoneal single-agent gemcitabine and Regimen II consisted of IFN-α and gemcitabine biweekly for 30 d.

RESULTS

Regimen I and II significantly decreased median tumor volume compared with control mice (P < 0.001). However, MiaPaCa-2 showed a more dramatic response to Regimen II compared with Panc-1 implanted mice. MiaPaCa-2 and treated with Regimen II showed less metastasis and less local invasion compared with Panc-1 treated with same regimen. Regimen II was more effective on MiaPaCa-2 compared with Regimen I (P < 0.001). There were no differences between Regimens I and II in the Panc-1 group.

CONCLUSIONS

Treatment of human pancreatic cancer in nude mice with interferon α and gemcitabine was associated with a reduction in tumor volume. This process was more prominent in the cells that express the interferon receptors.

Using lentiviral vectors for efficient pancreatic cancer gene therapy

Pancreatic cancer (PC) remains a life-threatening disease. Efficient therapeutic gene delivery to PC-derived cells continues to present challenges. We used self-inactivated lentiviral vectors to transduce PC-derived cells in vitro and in vivo. We showed that lentiviral vectors transduce PC-derived cell lines with high efficiency (>90%), regardless of the differentiation state of the cell. Next, we transferred human interferon beta (hIFN-beta) gene. Expression of hIFN-beta in PC cells using lentiviral vectors resulted in the inhibition of cell proliferation and the induction of cell death by apoptosis. In vivo, lentiviral administration of hIFN-beta prevented PC tumor progression for up to 15 days following gene therapy, and induced tumor regression/stabilization in 50% of the mice treated. Again, hIFN-beta expression resulted in cancer cell proliferation inhibition and apoptosis induction. We provide evidence that human immunodeficiency virus (HIV)-1-based lentiviral vectors are very efficient for gene transfer in PC-derived cells in vitro and in vivo. As a consequence, delivery of hIFN-beta stopped PC tumor progression. Thus, our approach could be applied to the 85% of PC patients with a locally advanced disease.

Potential role of type I interferons in the treatment of pituitary adenomas

Cytokines, particularly those endowed with pro-inflammatory properties, are known to influence the release of anterior pituitary hormones by a direct and indirect action at the level of pituitary gland and hypothalamus. Type I interferons (IFNs) represent a group of cytokines that act through a common receptor composed by two chains (IFNAR-1 and IFNAR-2). Several in vitro and in vivo studies underline the fact that type I IFNs are involved in the regulation of the immune-endocrine circuitry. Treatment with type I IFNs of patients affected by chronic viral hepatitis, multiple sclerosis and tumors influences the secretion of pituitary hormones. This article reviews the current knowledge about the effects of IFN-alpha and IFN-beta on hypothalamic-pituitary function and describes the potential role of type I IFNs in the treatment of pituitary adenomas.

Effects of type I interferons on IGF-mediated autocrine/paracrine growth of human neuroendocrine tumor cells

We recently demonstrated that interferon (IFN)-beta has a more potent antitumor activity than IFN-alpha in BON cells, a neuroendocrine tumor (NET) cell line. The present study showed the role of type I IFNs in the modulation of the insulin-like growth factor (IGF) system in NETs. BON cells expressed IGF-I, IGF-II, IGF-I receptor, and insulin receptor mRNA. In addition, IGF-I and IGF-II stimulated the proliferation of BON cells and induced an inhibition of DNA fragmentation (apoptosis). As evaluated by quantitative RT-PCR, treatment with IFN-alpha (100 IU/ml) or IFN-beta (100 IU/ml) inhibited the expression of IGF-II mRNA (-42% and -65%, respectively, both P < 0.001), whereas IGF-I receptor mRNA was significantly upregulated by IFN-alpha (+28%, P < 0.001) and downregulated by IFN-beta (-47%, P < 0.001). Immunoreactive IGF-II concentration decreased in the conditioned medium during IFN-alpha (-16%, P < 0.05) and IFN-beta (-69%, P < 0.001) treatment. Additionally, IGF-I receptor bioactivity was reduced (-54%) after IFN-beta treatment. Scatchard analysis of (125)I-labeled IGF-I binding to cell membrane of BON cells revealed a dramatic suppression of maximum binding capacity only in the presence of IFN-beta. Finally, the proapoptotic activity of IFN-beta was partially counteracted by the coadministration of IGF-I and IGF-II (both at 50 nM). In conclusion, these data demonstrate that the IGF system has an important role in autocrine/paracrine growth of BON cells. The more potent antitumor activity of IFN-beta compared with IFN-alpha could be explained by several effects on this system: 1) both IFNs inhibit the transcription of IGF-II, but the suppression is significantly higher after IFN-beta than IFN-alpha and 2) only IFN-beta inhibits the expression of IGF-I receptor.

Adjuvant intra-arterial chemotherapy and radiotherapy versus surgery alone in resectable pancreatic and periampullary cancer: a prospective randomized controlled trial

BACKGROUND

Success of surgical treatment for pancreatic and periampullary cancer is often limited due to locoregional recurrence and/or the development of distant metastases.

OBJECTIVE

The survival benefit of celiac axis infusion (CAI) and radiotherapy (RT) versus observation after resection of pancreatic or periampullary cancer was investigated.

METHODS

In a randomized controlled trial, 120 consecutive patients with histopathologically proven pancreatic or periampullary cancer received either adjuvant treatment consisting of intra-arterial mitoxantrone, 5-FU, leucovorin, and cisplatinum in combination with 30 x 1.8 Gy radiotherapy (group A) or no adjuvant treatment (group B). Groups were stratified for tumor type (pancreatic vs. periampullary tumors).

RESULTS

After surgery, 120 patients were randomized (59 patients in the treatment group, 61 in the observation group). The median follow-up was 17 months. No significant overall survival benefit was seen (median, 19 vs. 18 months resp.). Progressive disease was seen in 86 patients: in 37 patients in the CAI/RT group, and in 49 patients in the observation group (log-rank P < 0.02). Subgroup analysis showed significantly less liver metastases after adjuvant treatment in periampullary tumors (log-rank P < 0.03) without effect on local recurrence. Nonetheless, there was no significant effect on overall survival in these patients (log-rank P = 0.15). In patients with pancreatic cancer, CAI/RT had no significant effect on local recurrence (log-rank P = 0.12) neither on the development of liver metastases (log-rank P = 0.76) and consequently, no effect on overall survival.

CONCLUSION

This adjuvant treatment schedule results in a prolonged time to progression. For periampullary tumors, CAI/RT induced a significant reduction in the development of liver metastases, with a possible effect on overall survival. Especially in these tumors, CAI/RT might prove beneficial in larger groups and further research is warranted.

Inhibition of HBV gene expression and replication by stably expressed interferon-alpha1 via adeno-associated viral vectors

Background

Interferon‐α2 (IFNα2) is routinely used for anti‐hepatitis B virus (HBV) treatment. However, the therapeutic efficiency is unsatisfactory, particularly in East Asia. Such inefficiency might be a result of the short half‐life, relatively low local concentration and strong side‐effects of interferons. Frequent and repeated injection is also a big burden for patients. In the present study, a single dose of vector‐delivered IFNα1 was tested for its anti‐HBV effects.

Methods

Adeno‐associated viral vector (AAV‐IFNα1) was generated to deliver the IFNα1 gene into hepatocytes. IFNα1, hepatitis B surface (HBsAg) and e (HBeAg) antigens were measured by enzyme‐linked immunosorbent assay and/or western blotting. The level of viral DNA was measured by quantitative real‐time polymerase chain reaction.

Results

AAV‐IFNα1 effectively transduced HBV‐producing cells (HepAD38) and mouse hepatocytes, where IFNα1 was expressed in a stable manner. Both intracellular and extracellular HBsAg and HBeAg were significantly reduced in vitro. In the HBV‐producing mice, the concentration of IFNα1 in the liver was eight‐fold higher than that in plasma. Compared with control groups, HBeAg/HBsAg antigen levels were reduced by more than ten‐fold from day 1–5, and dropped to an undetectable level on day 9 in the AAV‐IFNα1 group. Concurrently, the level of viral DNA decreased over 30‐fold for several weeks.

Conclusions

A single dose administration of AAV‐IFNα1 viral vector displayed prolonged transgene expression and superior antiviral effects both in vitro and in vivo. Therefore, the use of AAV‐IFNα1 might be a potential alternative strategy for anti‐HBV therapy. Copyright © 2008 John Wiley & Sons, Ltd.