Growth hormone receptor promotes osteosarcoma cell growth and metastases

Cancer invasion and metastasis: Insights from murine pubertal mammary gland morphogenesis

Cancer invasion and metastasis accounts for the majority of cancer related mortality. A better understanding of the players that drive the aberrant invasion and migration of tumors cells will provide critical targets to inhibit metastasis. Postnatal pubertal mammary gland morphogenesis is characterized by highly proliferative, invasive, and migratory normal epithelial cells. Identifying the molecular regulators of pubertal gland development is a promising strategy since tumorigenesis and metastasis is postulated to be a consequence of aberrant reactivation of developmental stages. In this review, we summarize the pubertal morphogenesis regulators that are involved in cancer metastasis and revisit pubertal mammary gland transcriptome profiling to uncover both known and unknown metastasis genes. Our updated list of pubertal morphogenesis regulators shows that most are implicated in invasion and metastasis. This review highlights molecular linkages between development and metastasis and provides a guide for exploring novel metastatic drivers.

Hormone-Related Cancer and Autoimmune Diseases: A Complex Interplay to be Discovered

Neoplasic transformation is a continuous process that occurs in the body. Even before clinical signs, the immune system is capable of recognizing these aberrant cells and reacting to suppress them. However, transformed cells acquire the ability to evade innate and adaptive immune defenses through the secretion of molecules that inhibit immune effector functions, resulting in tumor progression. Hormones have the ability to modulate the immune system and are involved in the pathogenesis of autoimmune diseases, and cancer. Hormones can control both the innate and adaptive immune systems in men and women. For example androgens reduce immunity through modulating the production of pro-inflammatory and anti-inflammatory mediators. Women are more prone than men to suffer from autoimmune diseases such as systemic lupus erythematosus, psoriasis and others. This is linked to female hormones modulating the immune system. Patients with autoimmune diseases consistently have an increased risk of cancer, either as a result of underlying immune system dysregulation or as a side effect of pharmaceutical treatments. Epidemiological data on cancer incidence emphasize the link between the immune system and cancer. We outline and illustrate the occurrence of hormone-related cancer and its relationship to the immune system or autoimmune diseases in this review. It is obvious that some observations are contentious and require explanation of molecular mechanisms and validation. As a result, future research should clarify the molecular pathways involved, including any causal relationships, in order to eventually allocate information that will aid in the treatment of hormone-sensitive cancer and autoimmune illness.

HER4 Promotes Osteosarcoma Progression and Predicts Poor Prognosis through the PTEN-PI3K/AKT Pathway

Studies have reported a relationship between human epidermal growth factor receptor 4 (HER4), a ubiquitously expressed and unique member of the ErbB family, and clinicopathological features of osteosarcoma. However, further investigation is warranted. HER4 expression was analyzed by quantitative reverse transcription-polymerase chain reaction, western blotting, and immunohistochemistry. The relationship between HER4 expression and the prognosis of patients with osteosarcoma was determined by constructing a Kaplan-Meier curve. Cell viability and proliferation were investigated by MTT and colony formation assays. The mechanism underlying HER4-modulated proliferation and invasion/migration of osteosarcoma cells was determined by short hairpin RNA (shRNA) interference, colony formation, migration, invasion, and western blotting experiments. Spheroid formation assay and CD133+ cell populations were used to examine HER4-induced stem-like traits.

The present findings revealed that HER4 was overexpressed in both osteosarcoma cells and tissues. Moreover, this overexpression was associated with high Enneking stage, metastasis, and recurrence. Sh-HER4 showed obviously suppressed cell viability, colony formation, and invasion/migration. In addition, knockdown of HER4 markedly attenuated the spheroid size and proportion of CD133-positive cells, as well as the expression of stemness markers. Sh-HER4 also reduced the tumor size, downregulated the expression of phosphorylated-PI3K (p-PI3K) and p-AKT, and increased that of p-phosphatase and tensin homolog (p-PTEN) in mouse tissue. From a mechanistic perspective, HER4 knockdown activated p-PTEN and suppressed p-PI3K and p-AKT expression. HER4 promoted osteosarcoma progression through inactivation of the PTEN-PI3K/AKT pathway.

Taken together, the results indicate that HER4 represents a novel target in osteosarcoma progression and stemness modulation, and may be of value for the development of treatments against osteosarcoma.

Small molecules to regulate the GH/IGF1 axis by inhibiting the growth hormone receptor synthesis

Growth hormone (GH) and insulin-like growth factor-1 (IGF1) play an important role in mammalian development, cell proliferation and lifespan. Especially in cases of tumor growth there is an urgent need to control the GH/IGF1 axis. In this study we screened a 38,480-compound library, and in two consecutive rounds of analogues selection, we identified active lead compounds based on the following criteria: inhibition the GH receptor (GHR) activity and its downstream effectors Jak2 and STAT5, and inhibition of growth of breast and colon cancer cells. The most active small molecule (BM001) inhibited both the GH/IGF1 axis and cell proliferation with an IC50 of 10-30 nM of human cancer cells. BM001 depleted GHR in human lymphoblasts. In preclinical xenografted experiments, BM001 showed a strong decrease in tumor volume in mice transplanted with MDA-MB-231 breast cancer cells. Mechanistically, the drug acts on the synthesis of the GHR. Our findings open the possibility to inhibit the GH/IGF1 axis with a small molecule.

The inhibition of GHR enhanced cytotoxic effects of etoposide on neuroblastoma

Etoposide, a DNA damage-inducing agent, is widely used to treat neuroblastoma. Etoposide binds to and inhibits topoisomerase II, thereby inducing the DNA damage response. However, the underlying mechanism of etoposide resistance in neuroblastoma remains unclear. The results of the present study revealed that etoposide upregulated growth hormone receptor (GHR) expression levels in etoposide-resistant neuroblastoma cells, suggesting that GHR upregulation may be involved in the underlying mechanism of etoposide resistance. Thus, the combined effect of GHR knockdown and etoposide treatment on cell viability, apoptosis and migration in vitro, as well as tumor growth in mouse xenograft models in vivo, was subsequently analyzed. The results of cell viability and colony formation assays demonstrated that GHR knockdown enhanced the inhibitory effects of etoposide on cell viability and sensitized cells to etoposide. The enhanced cell viability was discovered to be, at least in part, due to the increase in etoposide-induced apoptosis following GHR knockdown. Moreover, the knockdown of GHR enhanced the inhibitory effect of etoposide on cell migration. Mouse xenograft studies confirmed the effects of GHR silencing in etoposide-resistant neuroblastoma progression in vivo. Furthermore, the effects of GHR knockdown in etoposide resistance were hypothesized to occur via the inactivation of the MEK/ERK signaling pathway. In conclusion, the results of the present study provided novel insight into the underlying mechanism of etoposide resistance and a potential target for the treatment of etoposide-resistant neuroblastoma.

Combination Therapy of Cisplatin and other Agents for Osteosarcoma: A Review

Background:

Osteosarcoma is the most common type of primary bone tumor in children and adolescents, which is associated with rapid progression and poor prognosis. Multimodal therapy is the most common approach utilized for osteosarcoma management, such as the application of chemotherapy in combination with surgery or radiation therapy. Cisplatin is one of the predominantly used chemotherapeutic agents for osteosarcoma. Optimally, it is employed in combination with other chemotherapeutic drugs along with surgery or radiation therapy. Despite the availability of numerous treatment approaches, the patient survival rate has not definitively improved over the past three decades.

Methods:

We have summarized all findings regarding the combination of cisplatin with other chemotherapeutic agents as well as with phytochemical compounds.

Results:

A combination of cisplatin with a phytochemical compound synergistically enhances the killing effect of cisplatin on osteosarcoma cells with fewer side effects compared to combination with other chemotherapeutic agents.

Conclusion:

Conclusively, a combination of cisplatin with selected chemotherapeutic drugs has been shown to be effective. However, the unchanged survival rate has posed an urge to search for a new combination regimen. As a collaborative effort to substantiate the therapeutic efficacy, the combination with phytochemical compounds shows a promising response both in vitro as well as in the preclinical study.

GH and IGF System: The Regulatory Role of miRNAs and lncRNAs in Cancer

Growth hormone (GH) and the insulin-like growth factor (IGF) system are involved in many biological processes and have growth-promoting actions regulating cell proliferation, differentiation, apoptosis and angiogenesis. A recent chapter in epigenetics is represented by microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) which regulate gene expression. Dysregulated miRNAs and lncRNAs have been associated with several diseases including cancer. Herein we report the most recent findings concerning miRNAs and lncRNAs regulating GH and the IGF system in the context of pituitary adenomas, osteosarcoma and colorectal cancer, shedding light on new possible therapeutic targets. Pituitary adenomas are increasingly common intracranial tumors and somatotroph adenomas determine supra-physiological GH secretion and cause acromegaly. Osteosarcoma is the most frequent bone tumor in children and adolescents and was reported in adults who were treated with GH in childhood. Colorectal cancer is the third cancer in the world and has a higher prevalence in acromegalic patients.

Alternative splicing of leptin receptor overlapping transcript in osteosarcoma

IMPACT STATEMENT

Osteosarcoma (OS, also known as osteogenic sarcoma) is the most common primary malignancy of bone in children and adolescents. The molecular mechanisms of OS are extremely complicated and its molecular mediators remain to be elucidated. We sequenced total RNA from 18 OS bone samples (paired normal-tumor biopsies). We found statistically significant (FDR <0.05) 26 differentially expressed transcript variants of LEPROT gene with different expressions in normal and tumor samples. These findings contribute to the understanding of molecular mechanisms of OS development and provide encouragement to pursue further research.

Growth hormone receptor promotes breast cancer progression via the BRAF/MEK/ERK signaling pathway

Growth hormone receptor (GHR), a member of the class I cytokine receptor family, plays key roles in cancer progression. Recently, GHR has been reported to be associated with breast cancer development, but the molecular mechanism of GHR in this malignancy is not fully understood. To investigate this issue, we stably inhibited GHR in breast cancer cell lines, which were observed to reduce cell proliferation, tumor growth and induction of apoptosis, and arrest the cell‐cycle arrest at the G1–S phase transition. In addition, GHR silencing suppressed the protein levels of B‐Raf proto‐oncogene, serine/threonine kinase (BRAF), Mitogen‐activated protein kinase kinase (MEK) and Extracellular regulated protein kinases (ERK). These findings suggest that GHR may mediate breast cell progression and apoptosis through control of the cell cycle via the BRAF/MEK/ERK signaling pathway.