Increased genome instability and oxidative DNA damage and their association with IGF-1 levels in patients with active acromegaly

IGF-I protects porcine granulosa cells from hypoxia-induced apoptosis by promoting homologous recombination repair through the PI3K/AKT/E2F8/RAD51 pathway

Severe hypoxia induced by vascular compromise (ovarian torsion, surgery), obliteration of vessels (aging, chemotherapy, particularly platinum drugs) can cause massive follicle atresia. On the other hand, hypoxia increases the occurrence of DNA double-strand breaks (DSBs) and triggers cellular damage repair mechanisms; however, if the damage is not promptly repaired, it can also induce the apoptosis program. Insulin-like growth factor-I (IGF-I) is a polypeptide hormone that plays essential roles in stimulating mammalian follicular development. Here, we report a novel role for IGF-I in protecting hypoxic GCs from apoptosis by promoting DNA repair through the homologous recombination (HR) process. Indeed, the hypoxic environment within follicles significantly inhibited the efficiency of HR-directed DNA repair. The presence of IGF-I-induced HR pathway to alleviate hypoxia-induced DNA damage and apoptosis primarily through upregulating the expression of the RAD51 recombinase. Importantly, we identified a new transcriptional regulator of RAD51, namely E2F8, which mediates the protective effects of IGF-I on hypoxic GCs by facilitating the transcriptional activation of RAD51. Furthermore, we demonstrated that the PI3K/AKT pathway is crucial for IGF-I-induced E2F8 expression, resulting in increased RAD51 expression and enhanced HR activity, which mitigates hypoxia-induced DNA damage and thereby protects against GCs apoptosis. Together, these findings define a novel mechanism of IGF-I-mediated GCs protection by activating the HR repair through the PI3K/AKT/E2F8/RAD51 pathway under hypoxia.

WIP1 is a novel specific target for growth hormone action

DNA damage repair (DDR) is mediated by phosphorylating effectors ATM kinase, CHK2, p53, and γH2AX. We showed earlier that GH suppresses DDR by suppressing pATM, resulting in DNA damage accumulation. Here, we show GH acting through GH receptor (GHR) inducing wild-type p53-inducible phosphatase 1 (WIP1), which dephosphorylated ATM and its effectors in normal human colon cells and three-dimensional human intestinal organoids. Mice bearing GH-secreting xenografts exhibited induced colon WIP1 with suppressed pATM and γH2AX. WIP1 was also induced in buffy coats derived from patients with elevated GH from somatotroph adenomas. In contrast, decreased colon WIP1 was observed in GHR-/- mice. WIP1 inhibition restored ATM phosphorylation and reversed GH-induced DNA damage. We elucidated a novel GH signaling pathway activating Src/AMPK to trigger HIPK2 nuclear-cytoplasmic relocation and suppressing WIP1 ubiquitination. Concordantly, blocking either AMPK or Src abolished GH-induced WIP1. We identify WIP1 as a specific target for GH-mediated epithelial DNA damage accumulation.

Down-regulation of hepatic expression of GHR/STAT5/IGF-1 signaling pathway fosters development and aggressiveness of HCV-related hepatocellular carcinoma: Crosstalk with Snail-1 and type 2 transforming growth factor-beta receptor

Background and aims

So far, few clinical trials are available concerning the role of growth hormone receptor (GHR)/signal transducer and activator of transcription 5 (STAT5)/insulin like growth factor-1 (IGF-1) axis in hepatocarcinogenesis. The aim of this study was to evaluate the hepatic expression of GHR/STAT5/IGF-1 signaling pathway in hepatocellular carcinoma (HCC) patients and to correlate the results with the clinico-pathological features and disease outcome. The interaction between this signaling pathway and some inducers of epithelial-mesenchymal transition (EMT), namely Snail-1 and type 2 transforming growth factor-beta receptor (TGFBR2) was studied too.

Material and methods

A total of 40 patients with HCV-associated HCC were included in this study. They were compared to 40 patients with HCV-related cirrhosis without HCC, and 20 healthy controls. The hepatic expression of GHR, STAT5, IGF-1, Snail-1 and TGFBR2 proteins were assessed by immunohistochemistry.

Results

Compared with cirrhotic patients without HCC and healthy controls, cirrhotic patients with HCC had significantly lower hepatic expression of GHR, STAT5, and IGF-1proteins. They also displayed significantly lower hepatic expression of TGFBR2, but higher expression of Snail-1 versus the non-HCC cirrhotic patients and controls. Serum levels of alpha-fetoprotein (AFP) showed significant negative correlations with hepatic expression of GHR (r = -0.31; p = 0.029) and STAT5 (r = -0.29; p = 0.04). Hepatic expression of Snail-1 also showed negative correlations with GHR, STAT5, and IGF-1 expression (r = -0.55, p = 0.02; r = -0.472, p = 0.035, and r = -0.51, p = 0.009, respectively), whereas, hepatic expression of TGFBR2 was correlated positively with the expression of all these proteins (r = 0.47, p = 0.034; 0.49, p = 0.023, and r = 0.57, p<0.001, respectively). Moreover, we reported that decreased expression of GHR was significantly associated with serum AFP level>100 ng/ml (p = 0.048), increased tumor size (p = 0.02), vascular invasion (p = 0.002), and advanced pathological stage (p = 0.01). Similar significant associations were found between down-regulation of STAT5 expression and AFP level > 100 ng/ml (p = 0.006), vascular invasion (p = 0.009), and advanced tumor stage (p = 0.007). Also, attenuated expression of IGF-1 showed a significant association with vascular invasion (p < 0.001). Intriguingly, we detected that lower expression of GHR, STAT5 and IGF-1 were considered independent predictors for worse outcome in HCC.

Conclusion

Decreased expression of GHR/STAT5/IGF-1 signaling pathway may have a role in development, aggressiveness, and worse outcome of HCV-associated HCC irrespective of the liver functional status. Snail-1 and TGFBR2 as inducers of EMT may be key players. However, large prospective multicenter studies are needed to validate these results.

Induction of endoplasmic reticulum stress markers in an acromegaly model

Acromegaly is a growth hormone (GH) excess pathological condition in humans. Acromegaly is associated with somatic disfigurement and a wide range of systemic manifestations such as arthritis, neuropathy, carpal tunnel syndrome, reproductive disorders, metabolic disorders, and gastrointestinal complications. The influence of excess GH on the cellular level could aid in understanding the root causes of acromegaly-related health complications. Previously, we found that GH excess induces DNA damage to somatic cells and reduces the stem cells number and causes premature aging. In this study, an in-depth analysis of the acromegaly RNAseq data revealed the disruption of important biological cellular processes. Gene set enrichment analysis, heatmap, and enrichment analysis of acromegaly RNAseq data revealed induction of endoplasmic reticulum (ER) stress markers in various organs. Interestingly, the induction of ER stress was even more apparent than in aged zebrafish. Splicing of box-binding protein-1 (XBP1) mRNA is a hallmark of ER stress. Therefore, we quantified spliced XBP1 mRNA in different organs of our acromegaly model. Thus, our study emphasizes the importance of ER stress in GH oversecretion, which is important for understanding the health complications of acromegaly.

Pituitary tumors and the risk of other malignancies: is the relationship coincidental or causal?

Pituitary adenomas are benign neoplasms of the pituitary. The most prevalent are prolactinomas and non-functioning pituitary adenomas, followed by growth hormone- and ACTH-secreting adenomas. Most pituitary adenomas seem to be sporadic and their persistent growth is very atypical. No molecular markers predict their behavior. The occurrence of pituitary adenomas and malignancies in the same patient can be either pure coincidence or caused by shared underlying genetic susceptibility involved in tumorigenesis. Detailed family history on cancers/tumors in the first, second and third generation of family members on each side of the family has been reported in a few studies. They found an association of pituitary tumors with positive family history for breast, lung and colorectal cancer. We have reported that in about 50% of patients with pituitary adenomas, an association with positive family history for cancer has been found independent of secretory phenotype (acromegaly, prolactinoma, Cushing's disease or non-functioning pituitary adenomas). We also found earlier onset of pituitary tumors (younger age at diagnosis of pituitary tumors) in patients with a strong family history of cancer. In our recent unpublished series of 1300 patients with pituitary adenomas, 6.8% of patients were diagnosed with malignancy. The latency period between the diagnosis of pituitary adenoma and cancer was variable, and in 33% of patients, it was longer than 5 years. Besides the inherited trophic mechanisms (shared underlying genetic variants), the potential influence of shared complex epigenetic influences (environmental and behavioral factors - obesity, smoking, alcohol intake and insulin resistance) is discussed. Further studies are needed to better understand if patients with pituitary adenomas are at increased risk for cancer.

Local non-pituitary growth hormone is induced with aging and facilitates epithelial damage

Microenvironmental factors modulating age-related DNA damage are unclear. Non-pituitary growth hormone (npGH) is induced in human colon, non-transformed human colon cells, and fibroblasts, and in 3-dimensional intestinal organoids with age-associated DNA damage. Autocrine/paracrine npGH suppresses p53 and attenuates DNA damage response (DDR) by inducing TRIM29 and reducing ATM phosphorylation, leading to reduced DNA repair and DNA damage accumulation. Organoids cultured up to 4 months exhibit aging markers, p16, and SA-β-galactosidase and decreased telomere length, as well as DNA damage accumulation, with increased npGH, suppressed p53, and attenuated DDR. Suppressing GH in aged organoids increases p53 and decreases DNA damage. WT mice exhibit age-dependent colon DNA damage accumulation, while in aged mice devoid of colon GH signaling, DNA damage remains low, with elevated p53. As age-associated npGH induction enables a pro-proliferative microenvironment, abrogating npGH signaling could be targeted as anti-aging therapy by impeding DNA damage and age-related pathologies.

Chesnokova et al. show that non-pituitary growth hormone (npGH) is induced in aging DNA-damaged colon epithelium and suppresses DNA damage response by attenuating the phosphorylation of DNA repair proteins. npGH induction promotes DNA damage accumulation, resulting in age-associated colon microenvironment changes. Accordingly, disrupted GH signaling in aging mice prevents accumulated DNA damage.

Dual Characters of GH-IGF1 Signaling Pathways in Radiotherapy and Post-radiotherapy Repair of Cancers

Radiotherapy remains one of the most important cancer treatment modalities. In the course of radiotherapy for tumor treatment, the incidental irradiation of adjacent tissues could not be completely avoided. DNA damage is one of the main factors of cell death caused by ionizing radiation, including single-strand (SSBs) and double-strand breaks (DSBs). The growth hormone-Insulin-like growth factor 1 (GH-IGF1) axis plays numerous roles in various systems by promoting cell proliferation and inhibiting apoptosis, supporting its effects in inducing the development of multiple cancers. Meanwhile, the GH-IGF1 signaling involved in DNA damage response (DDR) and DNA damage repair determines the radio-resistance of cancer cells subjected to radiotherapy and repair of adjacent tissues damaged by radiotherapy. In the present review, we firstly summarized the studies on GH-IGF1 signaling in the development of cancers. Then we discussed the adverse effect of GH-IGF1 signaling in radiotherapy to cancer cells and the favorable impact of GH-IGF1 signaling on radiation damage repair to adjacent tissues after irradiation. This review further summarized recent advances on research into the molecular mechanism of GH-IGF1 signaling pathway in these effects, expecting to specify the dual characters of GH-IGF1 signaling pathways in radiotherapy and post-radiotherapy repair of cancers, subsequently providing theoretical basis of their roles in increasing radiation sensitivity during cancer radiotherapy and repairing damage after radiotherapy.

Ageing genetic signature of hypersomatotropism

Acromegaly is a pathological condition that is caused by over-secretion of growth hormone (GH) and develops primarily from a pituitary adenoma. Excess GH exposure over a prolonged period of time leads to a wide range of systemic manifestations and comorbidities. Studying the effect of excess GH on the cellular level could help to understand the underlying causes of acromegaly health complications and comorbidities. In our previous publications, we have shown that excess GH reduces body side population (SP) stem cells and induces signs of premature ageing in an acromegaly zebrafish model. Here, we study acromegaly ageing in greater depth at the level of gene expression. We investigated whether acromegaly induces an ageing genetic signature in different organs. Using the GenAge database, our acromegaly model showed a significant enrichment of ageing genetic datasets in the muscle but not in other organs. Likewise, the hierarchical clustering of wild type (WT), acromegaly and aged RNA data from various organs revealed the similarity of gene expression profiles between the acromegaly and the aged muscles. We therefore identified overlapping differentially expressed genes (DEGs) in different organs between acromegaly and aged zebrafish. Importantly, about half of the muscle, liver and brain acromegaly DEGs overlapped with aged zebrafish DEGs. Interestingly, overlapping was observed in the same way; acromegaly-up DEGs overlapped with aged zebrafish up DEGs, not down DEGs, and vice versa. We then identified the biological functions of overlapping DEGs. Enrichment database analysis and gene ontology showed that most overlapping muscle genes were involved in ageing metabolism, while overlapping liver DEGs were involved in metabolic pathways, response to hypoxia and endoplasmic reticulum stress. Thus, this study provides a full ageing genetic signature of acromegaly at the gene expression level.

Growth Hormone and Aging: New Findings

Complex relationships between growth hormone (GH) signaling and mammalian aging continue to attract attention of many investigators. Recent results include evidence that the impact of GH on genome maintenance (DNA damage and repair) is drastically different in normal as compared to cancer cells, consistent with GH promoting aging and cancer progression. Impact of GH on DNA methylation was studied as a possible mechanism linking actions of GH during early life to the trajectory of aging. Animals with reduced or enhanced GH signaling and novel animals with adipocyte-specific deletion of GH receptors were used to elucidate the effects of GH on white and brown adipose tissue, including the impact of this hormone on lipolysis, fibrosis, and thermogenesis. Effects of GH on adipose tissue related to lipid and energy metabolism emerge as mechanistic links between GH, healthspan, and lifespan. Treatment of healthy men with a combination of GH, dehydroepiandrosterone, and metformin was reported to restore thymus function and reduce epigenetic age. Studies of human subjects with deficiency of GH or GH receptors and studies of mice with the same endocrine syndromes identified several phenotypic changes related (positively or negatively) to the previously reported predisposition to healthy aging. Results of these and other recent studies advance present understanding of the mechanisms by which GH influences aging and longevity and of the trade-offs involved.

Genomics and the Immune Landscape of Osteosarcoma

Conventional osteosarcoma (OS) is a high-grade intraosseous malignancy with production of osteoid matrix; however, a deeper dive into the underlying genetics reveals genomic complexity and instability that result in significant tumor heterogeneity. While early karyotyping studies demonstrated aneuploidy with chromosomal complexity and structural rearrangements, further investigations have identified few recurrent genetic alterations with the exception of the tumor suppressors TP53 and RB1. More recent studies utilizing next-generation sequencing (NGS; whole-exome sequencing, WES; and whole-genome sequencing, WGS) reveal a genomic landscape predominantly characterized by somatic copy number alterations rather than point/indel mutations. Despite its genomic complexity, OS has shown variable immune infiltrate and limited immunogenicity. In the current chapter, we review the hallmarks of OS genomics across recent NGS studies and the immune profile of OS including a large institutional cohort of OS patients with recurrent and metastatic disease. Understanding the genomic and immune landscape of OS may provide opportunities for translation in both molecularly targeted therapies and novel immuno-oncology approaches.

Peptide Hormone Regulation of DNA Damage Responses

DNA damage response (DDR) and DNA repair pathways determine neoplastic cell transformation and therapeutic responses, as well as the aging process. Altered DDR functioning results in accumulation of unrepaired DNA damage, increased frequency of tumorigenic mutations, and premature aging. Recent evidence suggests that polypeptide hormones play a role in modulating DDR and DNA damage repair, while DNA damage accumulation may also affect hormonal status. We review the available reports elucidating involvement of insulin-like growth factor 1 (IGF1), growth hormone (GH), α-melanocyte stimulating hormone (αMSH), and gonadotropin-releasing hormone (GnRH)/gonadotropins in DDR and DNA repair as well as the current understanding of pathways enabling these actions. We discuss effects of DNA damage pathway mutations, including Fanconi anemia, on endocrine function and consider mechanisms underlying these phenotypes. (Endocrine Reviews 41: 1 - 19, 2020).

Growth hormone in the tumor microenvironment

Tumor development is a multistep process whereby local mechanisms enable somatic mutations during preneoplastic stages. Once a tumor develops, it becomes a complex organ composed of multiple cell types. Interactions between malignant and non-transformed cells and tissues create a tumor microenvironment (TME) comprising epithelial cancer cells, cancer stem cells, non-tumorous cells, stromal cells, immune-inflammatory cells, blood and lymphatic vascular network, and extracellular matrix. We review reports and present a hypothesis that postulates the involvement of growth hormone (GH) in field cancerization. We discuss GH contribution to TME, promoting epithelial-to-mesenchymal transition, accumulation of unrepaired DNA damage, tumor vascularity, and resistance to therapy. Arch Endocrinol Metab. 2019;63(6):568-75.

Therapeutic effects of statins on chromosomal DNA damage of dyslipidemic patients

Statins are a group of cholesterol lowering drugs and frequently used in the therapy of dyslipidemia. Our knowledge of the impact of statin therapy on DNA damage is as yet rudimentary. In this study, we aimed to assess the possible (1) genotoxic, cytostatic, and cytotoxic effects of statins in peripheral blood lymphocytes by using the cytokinesis-block micronucleus cytome (CBMN-cyt) assay, and (2) oxidative DNA damage by measuring plasma 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels in response to statin therapy. Thirty patients with dyslipidemia who had no chronic diseases and did not use any medicines that interfere lipid values and twenty control subjects were included in the study. Statin therapy was initiated at risk-stratified doses. Blood samples were taken before and after treatment with statins and from control subjects, and CBMN-cyt assay parameters and 8-OHdG levels were evaluated. The chromosomal DNA damage (micronuclei and nucleoplasmic bridges [NPBs]), cytostasis (nuclear division index [NDI]), and cytotoxicity (apoptotic and necrotic cell frequencies) were decreased in patients with dyslipidemia after statin treatment. No significant differences were found for 8-OHdG levels between patients with dyslipidemia before or after statin therapy. The total cholesterol and low-density lipoprotein-cholesterol levels showed positive correlations with NPB frequency in patients with dyslipidemia prior to statin treatment. The present study is the first to evaluate CBMN-cyt assay biomarkers and 8-OHdG levels in patients with dyslipidemia before and after treatment with statins. The observed reductions of chromosomal DNA damage and NDI values with statin treatment could represent an important and under-appreciated pleiotropic effect of these agents.

Impact statement

In literature, it is possible to find some in vitro cytokinesis-block micronucleus (CBMN) assay studies about human lymphocytes and statins. But, there are no data on CBMN-cytome (CBMN-cyt) assay parameters related to statin therapy in patients with dyslipidemia. The present study is the first to evaluate CBMN-cyt assay biomarkers and 8-OHdG levels in patients with dyslipidemia before treatment and after treatment with statins (5–10 mg/day rosuvastatin or 10–20 mg/day atorvastatin). In this study we show that statin therapy decreased chromosomal DNA damage (micronuclei and nucleoplasmic bridges) and nuclear division index (NDI) values in patients with dyslipidemia by possible molecular reasons independent of oxidative DNA damage. In addition, the decrease of chromosomal DNA damage and NDI values with statin treatment could be indicated by the association between statin use and reduced risk of cancer.

Roles and mechanisms of SUMOylation on key proteins in myocardial ischemia/reperfusion injury

Myocardial ischemia/reperfusion (MI/R) injury has a great influence on the prognosis of patients with acute coronary occlusion. The underlying mechanisms of MI/R injury are complex. While the incidence of MI/R injury is increasing every year, the existing therapies are not satisfactory. Recently, small ubiquitin-related modifier (SUMO), which is a post-translational modification and involved in many cell processes, was found to play remarkable roles in MI/R injury. Several proteins that can be SUMOylated were found to interfere with different mechanisms of MI/R injury. Sarcoplasmic reticulum Ca²⁺ ATPase pump SUMOylation alleviated calcium overload. Among the histone deacetylase (HDAC) members, SUMOylation of HDAC4 reduced reactive oxygen species generation, whereas Sirt1 played protective roles in the SUMOylated form. Dynamic-related protein 1 modified by different SUMO proteins exerted opposite effects on the function of mitochondria. SUMOylation of hypoxia-inducible factors was fundamental in oxygen homeostasis, while eukaryotic elongation factor 2 SUMOylation induced cardiomyocyte apoptosis. The impact of other SUMOylation substrates in MI/R injury remains unclear. Here we reviewed how these SUMOylated proteins alleviated or exacerbated myocardial impairments by effecting the MI/R injury mechanisms. This may suggest methods for relieving MI/R injury in clinical practice and provide a reference for further study of SUMOylation in MI/R injury.

Growth Hormone Induces Colon DNA Damage Independent of IGF-1

DNA damage occurs as a result of environmental insults and aging and, if unrepaired, may lead to chromosomal instability and tumorigenesis. Because GH suppresses ataxia-telangiectasia mutated kinase phosphorylation, decreases DNA repair, and increases DNA damage accumulation, we elucidated whether GH effects on DNA damage are mediated through induced IGF-1. In nontumorous human colon cells, GH, but not IGF-1, increased DNA damage. Stably disrupted IGF-1 receptor (IGF-1R) by lentivirus-expressing short hairpin RNA in vitro or treatment with the IGF-1R phosphorylation inhibitor picropodophyllotoxin (PPP) in vitro and in vivo led to markedly induced GH receptor (GHR) abundance, rendering cells more responsive to GH actions. Suppressing IGF-1R triggered DNA damage in both normal human colon cells and three-dimensional human intestinal organoids. DNA damage was further increased when cells with disrupted IGF-1R were treated with GH. Because GH induction of DNA damage accumulation appeared to be mediated not by IGF-1R but probably by more abundant GH receptor expression, we injected athymic mice with GH-secreting xenografts and then treated them with PPP. In these mice, high circulating GH levels were associated with increased colon DNA damage despite disrupted IGF-1R activity (P < 0.01), whereas GHR levels were also induced. Further confirming that GH effects on DNA damage are directly mediated by GHR signaling, GHR-/- mice injected with PPP did not show increased DNA damage, whereas wild-type mice with intact GHR exhibited increased colon DNA damage in the face of IGF-1 signaling suppression. The results indicate that GH directly induces DNA damage independent of IGF-1.

Anthropometric characteristics, physical activity and risk of hematological malignancies: A systematic review and meta-analysis of cohort studies

Overweight/obesity, adult attained height and physical activity are possible risk factors for hematological malignancies. This meta-analysis aims to evaluate the associations between these factors and hematological cancer risk in adults. Eligible cohort studies were sought in PubMed up to May 31, 2016; overall, 44 studies were included in the present analyses. Pooled relative risk estimates were calculated using random-effects models; separate analyses were conducted for non-Hodgkin lymphoma (NHL) and subtypes (diffuse large B-cell lymphoma, DLBCL; follicular cell lymphoma; small lymphocytic lymphoma/chronic lymphocytic leukemia, SLL/CLL), Hodgkin lymphoma (HL), multiple myeloma (MM), leukemia and subtypes (acute lymphoblastic leukemia, acute myeloid leukemia, AML). Obesity was associated with increased risk of NHL, HL, MM, leukemia overall and AML in both sexes, as well as with higher DLBCL risk in women; the dose-response meta-regression analysis confirmed these associations. Less pronounced effects were observed regarding overweight, as it was associated with increased MM risk in both sexes, NHL risk in males, DLBCL and overall leukemia risk in females. Taller men presented with significantly higher risk of NHL and taller women were affected by higher risk of NHL, DLBCL, FL, CLL/SLL, MM, leukemia and AML. On the other hand, physical activity and abdominal fatness were not associated with the risk of hematological malignancies. In conclusion, this meta-analysis highlights the pivotal role of anthropometric measures in shaping the risk of hematological malignancies in adults. Additional, well-designed studies stemming from all the continents are needed for the further substantiation and generalization of the results.

A Zebrafish Acromegaly Model Elevates DNA Damage and Impairs DNA Repair Pathways

Acromegaly is a pathological condition due to excess growth hormone (GH) secretion. Acromegaly patients exhibit a deterioration of health and many associated complications, such as cardiovascular issues, arthritis, kidney diseases, muscular weakness, and colon cancer. Since these complications are generalized throughout the body, we investigated the effect of GH excess on cellular integrity. Here, we established stable acromegaly model zebrafish lines that overexpress tilapia GH and the red fluorescence protein (RFP) reporter gene for tracking GH gene expression throughout generations, and performed RNA-Seq data analysis from different organs. Intriguingly, heatmap and Expression2Kinases (X2K) analysis revealed the enrichment of DNA damage markers in various organs. Moreover, H2A.X immunostaining analysis in acromegaly zebrafish larvae and the adult acromegaly model brain and muscle showed a robust increase in the number of DNA-damaged cells. Using Gene Set Enrichment Analysis (GSEA), we found that the acromegaly zebrafish model had impaired DNA repair pathways in the liver, such as double-strand break (DSB), homologous recombination repair (HRR), non-homologous end joining (NHEJ), nucleotide excision repair (NER), and translesion synthesis (TLS). Interestingly, the impairment of DNA repair was even more prominent in acromegaly model than in aged zebrafish (three years old). Thus, our study demonstrates that affection of cellular integrity is characteristic of acromegaly.

Acromegaly: a challenging condition to diagnose

Acromegaly is an uncommon, chronic disease, characterized by hypersecretion of a pituitary growth hormone by somatotroph adenomas, along with increased levels of insulin-like growth factor-1. Although acromegaly presents a wide array of clinical manifestations, the salient symptoms include acral and soft tissue enlargement, joint pain, heart and respiratory failure, diabetes mellitus, and hypertension, leading to increased morbidity and mortality. Hence, early diagnosis of the disease is critical to enhance life expectancy and quality of life. New approaches are being developed for diagnosis and surveillance (both screening and follow-up), including sensitive biochemical assays and the use of MRI to visualize extremely small tumors, and are helpful in the early diagnosis of acromegaly, subsequent treatment, and disease control. This mini-review summarizes the most common and effective tools used in the diagnosis of acromegaly.

Heat shock protein 70 protects cardiomyocytes through suppressing SUMOylation and nucleus translocation of phosphorylated eukaryotic elongation factor 2 during myocardial ischemia and reperfusion

Myocardial ischemia and reperfusion (MIR) results in cardiomyocyte apoptosis with severe outcomes, which blocks cardiac tissue recovering from myocardial ischemia diseases. Heat shock protein 70 (HSP70) is one of protective molecule chaperones which could regulate the nucleus translocation of other proteins. In addition, eukaryotic elongation factor 2 (eEF2), which modulates protein translation process, is vital to the recovery of heart during MIR. However, the relationship between HSP70 and eEF2 and its effects on MIR are unclear. The expression and relationship between HSP70 and eEF2 is confirmed by western blot, immunoprecipitation in vitro using cardiomyocyte cell line H9c2 and in vivo rat MIR model. The further investigation was conducted in H9c2 cells with detection for cell-cycle and apoptosis. It is revealed that eEF2 interacted and be regulated by HSP70, which kept eEF2 as dephosphorylated status and preserved the function of eEF2 during MIR. In addition, HSP70 suppressed the nucleus translocation of phosphorylated eEF2, which inhibited cardiomyocyte apoptosis during myocardial reperfusion stage. Furthermore, HSP70 also interacted with C-terminal fragment of eEF2, which could reverse the nucleus translocation and cardiomyocyte apoptosis caused by N-terminal fragment of eEF2. HSP70 draw on advantage and avoid defect of MIR through regulating phosphorylation and nucleus translocation of eEF2.

Evaluation of chromosomal DNA damage, cytotoxicity, cytostasis, oxidative DNA damage and their relationship with endocrine hormones in patients with acute organophosphate poisoning

Pesticides are commonly used compounds in agriculture. Especially, organophosphates (OPs) are among the extensively used pesticides. Therefore, OPs poisoning is common, especially in underdeveloped and developing countries. Primary aim of this study was to research the effects of acute OPs poisoning on genome instability in the individuals' lymphocytes with acute OPs poisoning both by using the cytokinesis-block micronucleus cytome (CBMN-cyt) assay to examine chromosome/genome damage, cell proliferation index and cell death rate and by using the plasma 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels to determine oxidative DNA damage. Secondary aim of this study was also to assess whether a relation exists between endocrine hormones and the genome damage in acute OPs poisoning. In the study, blood samples were analysed of 13 patients before and after treatment admitted to the Department of Intensive Care Unit with acute OPs poisoning and of 13 healthy subjects of similar age and sex. The present study demonstrates that genome damage (micronucleus; MN and nucleoplasmic bridges; NPBs frequencies), apoptotic and necrotic cell frequencies increased in lymphocytes of patients with acute OPs poisoning before treatment and decreased after treatment. The present study also show that CBMN cyt assay parameters and 8-OHdG levels could be affected by some endocrine hormones such as E2, fT3, fT4, GH, IGF-1, FSH, LH, TSH, PRL, but not be related to ACTH and tT levels in acute OPs poisoning. In conclusion, it is believed that this is the first study to evaluate the chromosomal/oxidative DNA damage, cell proliferation, cell death and their associations with endocrine hormones in acute OPs poisoning. These preliminary findings need to be supported by further studies with larger sample sizes.

IGF-1 may predict the severity and outcome of patients with sepsis and be associated with microRNA-1 level changes

IGF-1 functions as an anti-oxidative stress molecule and some critical patients with sepsis have a lower level of serum IGF-1. However, the association between IGF-1 and the severity or prognosis of sepsis remains unclear. This study aimed to elucidate the relationship between serum IGF-1 levels and the severity and prognosis of sepsis, and the possible mechanism was analyzed. Clinical characteristics of patients with sepsis were recorded and analyzed. Serum IGF-1 levels and micro (mi)RNA-1 levels were tested using radioimmunoassay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, respectively. The A549 cell line and HKC cell line were cultured in vitro and exposed to H₂O₂ with or without IGF-1 treatment. Cell death was detected by analyzing cell death markers via ELISA kits, and miRNA-1 levels were detected after H₂O₂ exposure using RT-qPCR analysis. miRNA-1 in cells was upregulated by transfection and IGF-1 mRNA was detected to determine its relationship with miRNA-1. Once again, cell ELISA kits were used to analyze cell death markers after transfection. Serum IGF-1 levels were reduced in patients with sepsis, whereas miRNA-1 levels were higher (P<0.05 vs. healthy control). Patients in the septic shock subgroup or dead patients had the lowest IGF-1 levels and the highest miRNA-1 levels (P<0.05 vs. sepsis and severe sepsis). IGF-1 levels were inversely proportional to the miRNA-1 level. In vitro, IGF-1 reduced the cell death caused by H₂O₂. miRNA-1 transfection effectively increased the sensitivity of cells to H₂O₂ damage by reducing the expression of IGF-1, which was able to prevent cells from injury caused by H₂O₂. The transfection of negative control miRNA did not influence the level of IGF-1 miRNA and the sensitivity to H₂O₂ damage. In conclusion, low IGF-1 levels in patients with sepsis may predict increased severity of the condition and poor prognosis. The possible mechanism is that the excessive miRNA-1 levels reduce IGF-1 levels, resulting in insufficient anti-oxidative action by IGF-1 which increases the injury caused by oxidative stress in patients with sepsis.

Short-term, supra-physiological rhGH administration induces transient DNA damage in peripheral lymphocytes of healthy women

PURPOSE

While a good safety for recombinant human growth hormone (rhGH) therapy at replacement doses is recognized, a possible link between high concentration of the GH-IGF-I axis hormones and side negative effect has been reported. The aim of this pilot study was to assess whether a short-term exposure to supra-physiological doses of rhGH may affect DNA integrity in human lymphocytes (PBL).

METHODS

Eighteen healthy Caucasian female (24.2 ± 3.5 years) were randomly included in a Control (n = 9) and rhGH administration group (n = 9, 3-week treatment). DNA damage (comet assay), chromosomal breaks, and mitotic index in phytohemagglutinin-stimulated PBL were evaluated before (PRE), immediately (POST), and 30 days (POST30) after the last rhGH administration (0.029 mg kg^- 1 BW; 6 days/week), together with serum IGF-1 and IGFBP-3 concentrations.

RESULTS

rhGH administration increased IGF-I, without evidence of persisting IGF-I and IGFBP-3 changes 30 days after withdrawal. Total DNA breakage (% DNA in tails) was not significantly different in subjects treated with rhGH in comparison with controls, although the rhGH-treated subjects showed an higher percentage of heavily damaged nuclei immediately after the treatment (POST30 vs. PRE: p = 0.003), with a lower mitogenic potential of lymphocytes, detectable up to the POST30 (PRE vs. POST: p = 0.02; PRE vs. POST30: p = 0.007).

CONCLUSIONS

This pilot study showed that 3 weeks of short-term supra-physiological rhGH administration in healthy women induce a transient DNA damage and mitogenic impairment in PBL. The analysis of DNA damage should be explored as useful tool in monitoring the mid to long-term effects of high rhGH treatment or abuse.

Increased Chromosomal and Oxidative DNA Damage in Patients with Multinodular Goiter and Their Association with Cancer

Thyroid nodules are a common clinical problem worldwide. Although thyroid cancer accounts for a small percentage of thyroid nodules, the majority are benign. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) levels are a marker of oxidative stress and play a key role in the initiation and development of a range of diseases and cancer types. This study evaluates cytokinesis-block micronucleus cytome (CBMN-cyt) assay parameters and plasma 8-OHdG levels and their association with thyroid nodule size and thyroid hormones in patients with multinodular goiter. The study included 32 patients with multinodular goiter and 18 age- and sex-matched healthy controls. CBMN-cyt assay parameters in peripheral blood lymphocytes of patients with multinodular goiter and controls were evaluated, and plasma 8-OHdG levels were measured. The micronucleus (MN) frequency (chromosomal DNA damage), apoptotic and necrotic cells (cytotoxicity), and plasma 8-OHdG levels (oxidative DNA damage) were significantly higher among patients with multinodular goiter. Our study is the first report of increased chromosomal and oxidative DNA damage in patients with multinodular goiter, which may predict an increased risk of thyroid cancer in these patients. MN frequency and plasma 8-OHdG levels may be markers of the carcinogenic potential of multinodular goiters and could be used for early detection of different cancer types, including thyroid cancer.

Increased micronucleus, nucleoplasmic bridge, nuclear bud frequency and oxidative DNA damage associated with prolactin levels and pituitary adenoma diameters in patients with prolactinoma

Prolactinoma is the most common pituitary tumor. Most pituitary tumors are benign, but they often are clinically significant. We investigated cytokinesis-block micronucleus cytome (CBMN cyt) assay parameters and oxidative DNA damage in patients with prolactinoma to assess the relations among age, prolactin level, pituitary adenoma diameter and 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in patients with prolactinoma. We investigated 27 patients diagnosed with prolactinoma and 20 age- and sex-matched healthy controls. We measured CBMN cyt parameters and plasma 8-OHdG levels in peripheral blood lymphocytes of patients with prolactinoma and controls. The frequencies of micronucleus (MN), nucleoplasmic bridge, nuclear bud, apoptotic and necrotic cells, and plasma 8-OHdG levels in patients with prolactinoma were significantly greater than controls. MN frequency was correlated positively with age, prolactin levels and pituitary adenoma diameters in patients with prolactinoma. The increased chromosomal and oxidative DNA damage, and the positive correlation between MN frequency, prolactin levels and pituitary adenoma diameters may be associated with increased risk of cancer in patients with prolactinoma, because increased MN frequency is a predictor of cancer risk.

Accelerated Telomere Shortening in Acromegaly; IGF-I Induces Telomere Shortening and Cellular Senescence

OBJECTIVE

Patients with acromegaly exhibit reduced life expectancy and increased prevalence of age-related diseases, such as diabetes, hypertension, and cardiovascular disease. However, the underlying mechanism has not been fully elucidated. Telomere shortening is reportedly associated with reduced life expectancy and increased prevalence of these age-related diseases.

METHODS

We measured telomere length in patients with acromegaly using quantitative PCR method. The effect of GH and IGF-I on telomere length and cellular senescence was examined in human skin fibroblasts.

RESULTS

Patients with acromegaly exhibited shorter telomere length than age-, sex-, smoking-, and diabetes-matched control patients with non-functioning pituitary adenoma (0.62 ± 0.23 vs. 0.75 ± 0.35, respectively, P = 0.047). In addition, telomere length in acromegaly was negatively correlated with the disease duration (R2 = 0.210, P = 0.003). In vitro analysis revealed that not GH but IGF-I induced telomere shortening in human skin fibroblasts. Furthermore, IGF-I-treated cells showed increased senescence-associated β-galactosidase activity and expression of p53 and p21 protein. IGF-I-treated cells reached the Hayflick limit earlier than GH- or vehicle-treated cells, indicating that IGF-I induces cellular senescence.

CONCLUSION

Shortened telomeres in acromegaly and cellular senescence induced by IGF-I can explain, in part, the underlying mechanisms by which acromegaly exhibits an increased morbidity and mortality in association with the excess secretion of IGF-I.

Risk of Neoplasia in Pediatric Patients Receiving Growth Hormone Therapy--A Report From the Pediatric Endocrine Society Drug and Therapeutics Committee

CONTEXT

GH and IGF-1 have been shown to affect tumor growth in vitro and in some animal models. This report summarizes the available evidence on whether GH therapy in childhood is associated with an increased risk of neoplasia during treatment or after treatment is completed.

EVIDENCE ACQUISITION

A PubMed search conducted through February 2014 retrieved original articles written in English addressing GH therapy and neoplasia risk. Subsequent searches were done to include additional relevant publications.

EVIDENCE SYNTHESIS

In children without prior cancer or known risk factors for developing cancer, the clinical evidence does not affirm an association between GH therapy during childhood and neoplasia. GH therapy has not been reported to increase the risk for neoplasia in this population, although most of these data are derived from postmarketing surveillance studies lacking rigorous controls. In patients who are at higher risk for developing cancer, current evidence is insufficient to conclude whether or not GH further increases cancer risk. GH treatment of pediatric cancer survivors does not appear to increase the risk of recurrence but may increase their risk for subsequent primary neoplasms.

CONCLUSIONS

In children without known risk factors for malignancy, GH therapy can be safely administered without concerns about an increased risk for neoplasia. GH use in children with medical diagnoses predisposing them to the development of malignancies should be critically analyzed on an individual basis, and if chosen, appropriate surveillance for malignancies should be undertaken. GH can be used to treat GH-deficient childhood cancer survivors who are in remission with the understanding that GH therapy may increase their risk for second neoplasms.

The role of diabetes in acromegaly associated neoplasia

Background

The risk and mortality due to cancer in patients with acromegaly have been previously investigated. Although GH/IGF-1 excess provides a probable pathophysiological explanation, the degree of IGF-1 excess and the role in acromegaly-associated neoplasms of diabetes, a common comorbidity in acromegaly with known association with cancer, remains unclear.

Methods

Acromegalic patients treated in three Canadian referral centers (Toronto, Montreal, Edmonton) were included. All available clinical information was recorded including: age, initial and last percentage of the upper limit of normal (%ULN) IGF-1 levels, comorbidities and other neoplasms (benign and malignant).

Results

408 cases were assessed. 185 were women (45.3%), 126 (30.9%) developed extra-pituitary neoplasms: 55 malignant and 71 benign. The most frequent anatomic site was the gastrointestinal tract (46 [11.3%]), followed by head and neck (36 [8.8%]) and multiple locations (14 [3.4%]). 106 (26.0%) cases had diabetes. Initial IGF-1 was significantly higher in men older than 50 (380.15 vs. 284.78, p = 0.001) when compared to men younger than 50. Diabetics showed significantly higher initial IGF-1 (389.38 vs. 285.27, p = 0.009), as did diabetics older than 50 compared with those without diabetes. 45.3% (48/106) of cases with diabetes developed extra-pituitary neoplasms vs. 24.3% (71/292) without diabetes (p = 0.001, OR: 2.576 95%CI 1.615–4.108). 22.6% (24/106) of cases with diabetes developed malignant tumors vs. 9.2% (27/292), (p < 0.001, OR 2.873, 95%CI 1.572–5.250).

Conclusions

These data suggest that acromegalic patients with diabetes are more likely to develop extra-pituitary neoplasms and their initial IGF-1 levels are higher. The contribution of IGF-1 vs. diabetes alone or in combination in the development of extra-pituitary neoplasms warrants further investigation.