Influence of bicalutamide with or without tamoxifen or anastrozole on insulin-like growth factor 1 and binding proteins in prostate cancer patients

Androgen receptor is a potential novel prognostic marker and oncogenic target in osteosarcoma with dependence on CDK11

Osteosarcoma is the most common bone cancer in children and adolescents. Previously, we have found that cyclin-dependent kinase 11 (CDK11) signaling was essential for osteosarcoma cell growth and survival. Subsequently, CDK11 siRNA gene targeting, expression profiling, and network reconstruction of differentially expressed genes were performed between CDK11 knock down and wild type osteosarcoma cells. Reconstructed network of the differentially expressed genes pointed to the AR as key to CDK11 signaling in osteosarcoma. CDK11 increased transcriptional activation of AR gene in osteosarcoma cell lines. AR protein was highly expressed in various osteosarcoma cell lines and patient tumor tissues. Tissue microarray analysis showed that the disease-free survival rate for patients with high-expression of AR was significantly shorter than for patients with low-expression of AR. In addition, AR gene expression knockdown via siRNA greatly inhibited cell growth and viability. Similar results were found in osteosarcoma cells treated with AR inhibitor. These findings suggest that CDK11 is involved in the regulation of AR pathway and AR can be a potential novel prognostic marker and therapeutic target for osteosarcoma treatment.

Tamoxifen for the management of breast events induced by non-steroidal antiandrogens in patients with prostate cancer: a systematic review

BACKGROUND

Tamoxifen has emerged as a potential management option for gynecomastia and breast pain due to non-steroidal antiandrogens, and it is considered an alternative to surgery or radiotherapy. The objective of this systematic review was to assess the benefits and harms of tamoxifen, in comparison to other treatment options, for either the prophylaxis or treatment of breast events induced by non-steroidal antiandrogens in prostate cancer patients.

METHODS

We searched CENTRAL, MEDLINE, EMBASE, reference lists, the abstracts of three major conferences and three trial registers to identify ongoing randomized controlled trials (RCTs). Two authors independently screened the articles identified, assessed the trial quality and extracted data. The protocol was prospectively registered (CRD42011001320; http://www.crd.york.ac.uk/PROSPERO).

RESULTS

Four studies were identified. Tamoxifen significantly reduced the risk of suffering from gynecomastia (risk ratio 9RR0 0.10, 95% CI 0.05 to 0.22) or breast pain (RR 0.06, 95% CI 0.02 to 0.17) at six months compared to untreated controls. Tamoxifen also showed a significant benefit for the prevention of gynecomastia (RR 0.22, 95% CI 0.08 to 0.58) and breast pain (RR 0.25, 95% CI 0.10 to 0.64) when compared to anastrozole after a median of 12 months. One study showed a significant benefit of tamoxifen for the prevention of gynecomastia (RR 0.24, 95% CI 0.09 to 0.65) and breast pain (RR 0.20, 95% CI 0.06 to 0.65) when compared with radiotherapy at six months. Radiotherapy increased the risk of suffering from nipple erythema and skin irritation, but there were no significant differences for any other adverse events (all P>0.05).

CONCLUSIONS

The currently available evidence suggests good efficacy of tamoxifen for the prevention and treatment of breast events induced by non-steroidal antiandrogens. The impact of tamoxifen therapy on long-term adverse events, disease progression and survival remains unclear. Further large, well-designed RCTs, including long-term follow-ups, are warranted. Also, the optimal dose needs to be clarified.

Estrogen upregulates the IGF-1 signaling pathway in lung cancer through estrogen receptor-β

The estrogen receptor (ER) signaling and the insulin-like growth factor-1 receptor (IGF-1R) signaling are implicated in lung cancer progression. Here, we sought to investigate whether estrogen regulated the IGF-1R signaling in non-small cell lung cancer (NSCLC) and the underlying mechanisms. We examined and analyzed the correlation of the expression of aromatase (Arom), ERβ, ERα, insulin-like growth factor-1 (IGF-1), and IGF-1R in NSCLC. Tissue-microarray and immunohistochemistry analysis of tissue specimens from 162 NSCLC patients and 38 patients with benign pulmonary lesions showed that Arom, ERβ, IGF-1, and IGF-1R were overexpressed while ERα was not expressed in NSCLC. Furthermore, ERβ expression was positively correlated with that of Arom, IGF-1, and IGF-1R (r=0.554, 0.649, 0.496, respectively, P values are equal to 0.000), while Arom expression was positively associated with that of IGF-1 and IGF-1R (r=0.657, 0.714, respectively, P values are equal to 0.000). Additionally, ERβ, IGF-1, and phospho-IGF-1R, but not ERα, were expressed in A549 cells. Immunoblotting assays showed that A549 cells treated with E2 showed significantly higher IGF-1 and p-IGF-1R levels than those receiving the combination treatment of 17β-estradiol (E2) and fulvestrant (Ful, ER antagonist) (P=0.042, 0.002, respectively) or controls (P values are equal to 0.000). The MTT assays further revealed that E2 and IGF-1 synergistically promoted A549 cell proliferation. Together, our study provides the first direct evidence for an interaction between ER and IGF-1R in lung cancer. We showed that estrogen upregulated the IGF-1R signaling through ERβ in lung cancer tissues and A549 cells. These findings shed further light on the mechanisms whereby estrogen promotes lung cancer and highlight the ER and IGF-1R signaling pathways as promising targets for combinational therapy for lung cancer.