Micronucleus evaluation in mitogen-stimulated lymphocytes of patients with acromegaly

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.

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.

Outcomes of Transsphenoidal Surgery in Growth Hormone-Secreting Pituitary Adenomas

Growth hormone (GH)-secreting pituitary adenomas (PA) make up 15 to 20% of total amount of hormonally active adenomas. In addition to acromegaly and gigantism, these tumors cause deep metabolic disturbances. Its systemic impact leads to increased mortality ratio of 1.32 compared with general population. Surgical removal remains the priority treatment option in controlling acromegaly and provides endocrinologic remission in up to 72% patients. A total of 92 patients were included in the study. All surgeries were performed via microscopic transsphenoidal approach (TSA) by the senior author in our institution between December 2009 and October 2019. Only patients who were followed-up with 75 g oral glucose tolerance tests (OGTTs), GH, and insulin-like growth factor I (IFG-I) measurements preoperatively, 1 week, and every 6 months postoperatively were analyzed. Based on standard preoperative 1.5-T MR imaging with contrast enhancement, the adenomas were identified and distributed according to the size and KNOSP classification. The efficacy depends on KNOSP grade, which is directly correlated with invasiveness to cavernous sinus (CS). Grades 3 and 4 are unfavorable factors influencing prognosis. Excluding grade 0 adenomas, as the surgery was not difficult with the excellent outcomes, we reached 75% (36 out of 48) remission in grade 1 to 2 groups. In contrast, only 17% (2 out of 12) had successful outcomes after surgery alone. In conclusion, the study demonstrates the efficiency of TS surgery in patients with confirmed GH-secreting PA.

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.

The molecular origins and pathophysiological consequences of micronuclei: New insights into an age-old problem

Micronuclei (MN), the small nucleus-like bodies separated from the primary nucleus, can exist in cells with numerical and/or structural chromosomal aberrations in apparently normal tissues and more so in tumors in humans. While MN have been observed for over 100 years, they were merely and constantly considered as passive indicators of chromosome instability (CIN) for a long time. Relatively little is known about the molecular origins and biological consequences of MN. Rapid technological advances are helping to close these gaps. Very recent studies provide exciting evidence that MN act as key platform for chromothripsis and a trigger of innate immune response, suggesting that MN could affect cellular functions by both genetic and nongenetic means. These previously unappreciated findings have reawakened widespread interests in MN. In this review, the diverse mechanisms leading to MN generation and the complex fate profiles of MN are discussed, together with the evidence for their contribution to CIN, inflammation, senescence and cell death. Moreover, we put this knowledge together into a speculative perspective on how MN may be responsible for cancer development and how their presence may influence the choice of treatment. We suggest that the heterogeneous responses to MN may function physiological to ensure the arrestment, elimination and immune clearance of damaged cells, but pathologically, may enable the survival and oncogenic transformation of cells bearing CIN. These insights not only underscore the complexity of MN biology, but also raise a host of new questions and provide fertile ground for future research.

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.

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.

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 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.

Investigation of genotoxicity in acromegaly from peripheral blood lymphocyte cultures using a micronucleus assay

CONTEXT

Although patients with acromegaly may have an increased risk of developing several types of cancers, the degree of risk for malignancy in these patients is unresolved.

OBJECTIVE

The present study aimed to investigate the potential genotoxic effects of acromegaly on the cell cycle in peripheral blood lymphocyte cultures.

DESIGN

This was a single center, crossover, case-control study conducted on the acromegalic patients in Turkey.

SETTING

The study was conducted in the outpatient clinic of a university hospital.

PATIENTS

Seventy-one consecutively screened acromegalic patients and 56 controls participated in the study.

INTERVENTION

Patients were included, regardless of the disease activity status and their treatment duration before the study.

MAIN OUTCOME MEASURES

The primary end point was the frequency of micronucleus (MN) in the peripheral blood lymphocyte cultures, and the secondary end point was its clinical correlations.

RESULTS

The MN level was 3.82 ± 1.49 in the control group and 18.00 ± 6.13 in the acromegalic group (P < .01), whereas the nuclear division index (NDI) was 1.79 ± 0.12 in the control group and 1.68 ± 0.07 in the acromegalic group (P < .01). Neither MN nor NDI was correlated with age, GH, IGF-I, initial GH, initial IGF-I, duration of the remission period, and initial tumor size. Only the MN level was positively correlated with the duration of disease (r = 0.323, P = .014).

CONCLUSION

Our results indicated that acromegalic patients had genotoxic damage at a substantial level, and there was a positive correlation between the duration of disease and genotoxicity level.

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

OBJECTIVE

The objectives of this study were to assess cytokinesis-block micronucleus cytome (CBMN Cyt) assay parameters and also oxidative DNA damage in patients with active acromegaly and controls and to assess the relationship between age, serum insulin-like growth factor 1 (IGF-1) levels, pituitary adenoma diameters, 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and CBMN Cyt assay parameters in patients with active acromegaly.

DESIGN

The study population included 30 patients with active acromegaly and 30 age- and sex-matched healthy controls. CBMN Cyt assay parameters in peripheral blood lymphocytes of patients with active acromegaly and controls were evaluated and plasma 8-OHdG levels were measured.

RESULTS

Frequencies of micronucleus (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in lymphocytes of patients with acromegaly were found to be significantly higher than those in controls (p<0.001, p<0.001, p<0.001, respectively). The frequencies of apoptotic and necrotic cells in lymphocytes of patients with acromegaly were found to be significantly higher than those in controls (p<0.001 and p<0.001 respectively). No statistically significant differences in the number of cells in metaphase, the number of bi-nucleated cells (M2), the number of tri-nucleated cells (M3), the number of tetra-nucleated cells (M4) and nuclear division index (NDI) values were observed between patients and controls (p>0.05). Plasma 8-OHdG (ng/ml) levels in patients with acromegaly were found to be significantly higher than those in controls (p<0.005). MN frequency in the lymphocytes of patients with acromegaly increased with elevated serum IGF-1 levels (p<0.05), whereas the number of NPBs and the frequency of apoptotic cells decreased with elevated serum IGF-1 levels (p<0.01 and p<0.05 respectively).

CONCLUSIONS

Both the increase in chromosomal/oxidative DNA damage and the positive association between MN frequency and serum IGF-1 levels may predict an increased risk of malignancy in acromegalic patients. Long-term follow-up of patients with acromegaly will be necessary to establish the degree of cancer risk in this population.

Investigation of genome instability in patients with non-alcoholic steatohepatitis

AIM: To evaluate the occurrence of micronucleus (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in the mitogen-stimulated lymphocytes of patients with non-alcoholic steatohepatitis (NASH).

METHODS: The study was performed in 25 (9 females, 16 males) patients newly diagnosed with NASH, and 25 healthy subjects of similar ages and genders were used as a control group. None of the controls was known to be receiving any drugs for medical or other reasons or using alcohol. Hepatosteatosis was further excluded by abdominal ultrasound imaging in the control group. The numbers of MN, NPBs and NBUDs scored in binucleated (BN) cells were obtained from the mitogen-stimulated lymphocytes of patients and control subjects. Statistical comparisons of the numbers of BN cells with MN, NPBs and NBUDs and ages between the patients with NASH and control subjects were performed.

RESULTS: The mean ages of the patients and the control group were 41.92 ± 13.33 and 41.80 ± 13.09 years (P > 0.05), respectively. The values of the mean body mass index (BMI), HOMA-IR, hemoglobin, creatinin, aspartate aminotransferase, alanine aminotransferase, triglyceride, high density lipoprotein, and low density lipoprotein were 31.19 ± 4.62 kg/m²vs 25.07 ± 4.14 kg/m², 6.71 ± 4.68 vs 1.40 ± 0.53, 14.73 ± 1.49 g/dL vs 14.64 ± 1.30 g/dL, 0.74 ± 0.15 mg/dL vs 0.80 ± 0.13 mg/dL, 56.08 ± 29.11 U/L vs 16.88 ± 3.33 U/L, 92.2 ± 41.43 U/L vs 15.88 ± 5.88 U/L, 219.21 ± 141.68 mg/dL vs 102.56 ± 57.98 mg/dL, 16.37 ± 9.65 mg/dL vs 48.72 ± 15.31 mg/dL, and 136.75 ± 30.14 mg/dL vs 114.63 ± 34.13 mg/dL in the patients and control groups, respectively. The total numbers and frequencies of BN cells with MN, NPBs and NBUDs, which were scored using the CBMN cytome assay on PHA-stimulated lymphocytes, were evaluated in the patients with NASH and control group. We found significantly higher numbers of MN, NPBs and NBUDs in the BN cells of patients with NASH than in those of the control subjects (21.60 ± 9.32 vs 6.88 ± 3.91; 29.28 ± 13.31 vs 7.84 ± 3.96; 15.60 ± 5.55 vs 4.20 ± 1.63, respectively, P < 0.0001).

CONCLUSION: The increased numbers of MN, NPBs and NBUDs observed in the lymphocytes obtained from patients with NASH may reflect genomic instability.

Evaluation of genotoxicity, cytotoxicity and cytostasis in human lymphocytes exposed to patulin by using the cytokinesis-block micronucleus cytome (CBMN cyt) assay

Patulin (PAT) is a fungal secondary metabolite commonly present in apples and apple products. In the present study, PAT was evaluated for its genotoxic, cytotoxic and cytostatic effects to human peripheral blood lymphocytes by using the cytokinesis-block micronucleus cytome (CBMN Cyt) assay. Lymphocyte cultures were treated with PAT at the following concentrations, 0.1, 0.3, 0.5, 1.0, 2.5, 5.0, and 7.5 μM, as well as 0.5 μM mitomycin c (MMC) as a positive control and dimethyl sulfoxide (DMSO) as a vehicle control. PAT was found to induce nucleoplasmic bridges (NPBs) at 5.0 and 7.5 μM concentrations (P < 0.05), apoptotic cells at 0.1, 1.0, 5.0 μM (P < 0.05), 7.5 μM concentrations (P < 0.01) and necrotic cells at 0.3 and 2.5 μM (P < 0.05), 5.0 and 7.5 μM (P < 0.01) concentrations in human lymphocytes. The 2.5, 5.0, and 7.5 μM PAT concentrations also led to a clear decrease in the nuclear division index (NDI) (P < 0.05). PAT caused a significant dose-dependent increase in the number cells of NPBs, in the frequency of apoptotic and necrotic cells, and a significant dose-dependent decrease in the NDI values in lymphocytes. These results indicate that PAT at high concentrations is genotoxic, cytotoxic and cytostatic in cultured human lymphocytes.