Serum and intratumoural GH and IGF-I concentrations: Prognostic factors in the outcome of canine mammary cancer

Evaluation of circulating IGF-I and IGFBP-3 as biomarkers for tumors in dogs

Background

Serum-based parameters are considered non-invasive biomarkers for cancer detection. In human studies, insulin-like growth factor-I and II (IGF-I and IGF-II) and insulin-like growth factor binding protein-3 (IGFBP-3) are useful as diagnostic or prognostic markers and potential therapeutic targets.

Objectives

This study examined the diagnostic utility of circulating IGF-I, IGF-II, and IGFBP-3 levels in healthy dogs and dogs with tumors.

Methods

The serum concentrations of these biomarkers in 86 dogs with tumors were compared with those in 30 healthy dogs using an enzyme-linked immunosorbent assay (ELISA).

Results

The ELISA results showed no difference between healthy dogs and dogs with tumors in the serum IGF-II concentrations. On the other hand, there was a significant difference in the circulating IGF-I and IGFBP-3 levels between healthy dogs and dogs with tumors. The concentrations of serum IGF-I (median [interquartile range], 103.4 [59.5–175] ng/mL) in dogs with epithelial tumors were higher than those (58.4 ng/mL [43.5–79.9]) in healthy dogs. Thus, the concentrations of serum IGFBP-3 (43.4 ng/mL [33.2–57.2]) in dogs with malignant mesenchymal tumors were lower than those (60.8 ng/mL [47.6–70.5]) in healthy dogs.

Conclusions

The serum IGF-I and IGFBP-3 levels can be used as diagnostic biomarkers in dogs with tumors.

Immunohistochemical study of IGF-I and IGF-II expression in canine mammary tumours: Prognostic and diagnostic role

Mammary tumours are among the most common tumours in dogs and are of interest due to their similarities to human breast tumours. Insulin-like growth factors (IGFs) are considered important in cell growth and development. The aim of this study was to investigate the immunohistochemical expression of IGF-I and IGF-II in benign and malignant canine mammary tumours. In this study, 10 benign and 10 malignant mammary tumours from the archives of the Department of Pathology were used, and five normal breast tissues were used as controls. It was observed that the expression of IGF-I and IGF-II was low to absent in benign tumours and increased in malignant tumours. The expression of IGF-II was higher than that of IGF-I. This study showed that IGF-I and IGF-II can be used as criteria for malignancy in canine mammary tumours. The results also indicate that IGF-I and IGF-II may be used as early diagnostic markers, and their inhibition may be used for the treatment of canine and human mammary tumours in the future.

Targeting IRS-1/mPGES-1/NOX2 to inhibit the inflammatory response caused by insulin-like growth factor-I-induced activation of NF-κB and NLRP3 in cancer cells

The levels of insulin-like growth factor-l (IGF-1) and reactive oxygen species (ROS) are abnormally elevated in various tumour tissues, and IGF-1 has been reported to be associated with the development and progression of inflammation in cancers. In this study, we found that IGF-1 activated nuclear factor-κB (NF-κB) and NLRP3 inflammatory signalling via IRS-1/mPGES-1/NOX2-regulated ROS. Additionally, in the B16-F10 tumour-bearing mouse model, the number of tumours, tumour growth, invasion of tissues and expression of proinflammatory factors in peripheral blood were significantly decreased by treatment with an inhibitor combination compared with those of the IGF-1 group. Taken together, targeting IRS-1/mPGES-1/NOX2 to inhibit inflammation related to NF-κB and NLRP3 is a potential strategy for controlling the development and progression of cancer.

Acute phase proteins and biomarkers of oxidative status in feline spontaneous malignant mammary tumours

Acute phase proteins (APP) and biomarkers of oxidative status change in human and canine mammary tumours, however, they have not been studied in feline mammary tumours. The aims of this study were to investigate the APP and antioxidant responses in feline malignant mammary tumours, to evaluate their relation with tumour features, and to assess their prognostic value. Serum amyloid A (SAA), haptoglobin (Hp), albumin, butyrylcholinesterase (BChE), insulin-like growth factor1 (IGF1), paraoxonase1 (PON1), total serum thiols (Thiol), glutathione peroxidase (GPox) and total antioxidant capacity determined by different assays, including trolox equivalent antioxidant capacity assessed by two different methodologies (TEAC1/2), ferric reducing ability of plasma (FRAP), and cupric reducing antioxidant capacity (CUPRAC), were determined in serum of 50 queens with spontaneous mammary carcinomas and of 12 healthy female cats. At diagnosis, diseased queens presented significantly higher SAA and Hp, and lower albumin, BChE, GPox, TEAC1, TEAC2 and CUPRAC than controls. Different tumour features influenced concentrations of APP and antioxidants. Increases in serum Hp, and decreases in albumin, Thiol and FRAP were significantly associated with neoplastic vascular emboli, metastasis in regional lymph nodes and/or in distant organs. Distant metastasis development during the course of the disease was associated with increases in SAA and TEAC1. At diagnosis, decreased albumin was associated with a longer survival, and BChE <1.15 μmoL/mL.minute was associated with a shorter survival time on multivariate analysis. Feline malignant mammary tumours are associated with an APP response and oxidative stress, and different tumour features influence the inflammatory response and the oxidative damage. Furthermore, some of these analytes proved to have prognostic value.

Serum evaluation of leptin, IL-6, IGF-1 and estrogen in obese bitches with early stages of mammary carcinoma

ABSTRACT The aim of this study was to relate the serum concentration IL-6, IGF-1, leptin and estrogen in non-castrated bitches with or without overweight and early stage mammary carcinomas. Forty-three bitches were divided into four groups, two groups without mammary carcinomas with and without overweight, and two groups with mammary carcinomas with and without overweight. Overweight bitches, with or without mammary carcinomas, were statistically different from bitches by ideal weight, in relation to ECC, IMCC and body fat percentages (P< 0.0001). There was a positive correlation between ECC and IMCC (P< 0.0001), ECC and % GC (P< 0.0001), and IMCC and % GC (P< 0.0001). A positive correlation was found between serum leptin and IL-6 (P= 0.0451) and leptin and IGF-1 (P= 0.05). A positive correlation (P= 0.0053) between ECC and leptin was found in the analysis of body evaluation methods and serum concentrations, and a negative correlation between ECC and IL-6 (P= 0.0435). Among the fat percentage and the leptin concentration, there was a positive correlation (P= 0.0016), as found between the IMCC and leptin (P= 0, 0209). In this study, no association was observed between excessive weight and the presence of early stage mammary carcinomas.

Canine mammary tumors as a model for human disease

Animal models for examining human breast cancer (HBC) carcinogenesis have been extensively studied and proposed. With the recent advent of immunotherapy, significant attention has been focused on the dog as a model for human cancer. Dogs develop mammary tumors and other cancer types spontaneously with an intact immune system, which exhibit a number of clinical and molecular similarities to HBC. In addition to the spontaneous tumor presentation, the clinical similarities between human and canine mammary tumors (CMT) include the age at onset, hormonal etiology and course of the diseases. Furthermore, factors that affect the disease outcome, including tumor size, stage and lymph node invasion, are similar in HBC and CMT. Similarly, the molecular characteristics of steroid receptor, epidermal growth factor, proliferation marker, metalloproteinase and cyclooxygenase expression, and the mutation of the p53 tumor suppressor gene in CMT, mimic HBC. Furthermore, ductal carcinomas in situ in human and canine mammary glands are particularly similar in their pathological, molecular and visual characteristics. These CMT characteristics and their similarities to HBC indicate that the dog could be an excellent model for the study of human disease. These similarities are discussed in detail in the present review, and are compared with the in vitro and other in vivo animal models available.

Capromorelin: a ghrelin receptor agonist and novel therapy for stimulation of appetite in dogs

Ghrelin is a hormone, secreted from cells in the stomach, which is important in the regulation of appetite and food intake in mammals. It exerts its action by binding to a specific G-protein-coupled receptor, the growth hormone secretagogue receptor 1a (GHS-R1a) which is found in areas of the brain associated with the regulation of food intake. Ghrelin causes a release of growth hormone (GH) through binding to GHS-R1a in the hypothalamus and pituitary gland. A class of compounds known as growth hormone secretagogues, or ghrelin receptor agonists, were developed for therapeutic use in humans for the stimulation of GH in the frail elderly, and have subsequently been studied for their effects on increasing appetite and food intake, increasing body weight, building lean muscle mass, and treating cachexia. Subsequent research has shown that ghrelin has anti-inflammatory and immunomodulatory effects. This article reviews the basic physiology of ghrelin and the ghrelin receptor agonists, including the available evidence of these effects in vitro and in vivo in rodent models, humans, dogs and cats. One of these compounds, capromorelin, has been FDA-approved for the stimulation of appetite in dogs (ENTYCE ®). The data available on the safety and effectiveness of capromorelin is reviewed, along with a discussion of the potential clinical applications for ghrelin receptor agonists in both human and veterinary medicine.

Tumour-Derived Human Growth Hormone As a Therapeutic Target in Oncology

The growth hormone (GH) and insulin-like growth factor-1 (IGF1) axis is the key regulator of longitudinal growth, promoting postnatal bone and muscle growth. The available data suggest that GH expression by tumour cells is associated with the aetiology and progression of various cancers such as endometrial, breast, liver, prostate, and colon cancer. Accordingly there has been increased interest in targeting GH-mediated signal transduction in a therapeutic setting. Because GH has endocrine, autocrine, and paracrine actions, therapeutic strategies will need to take into account systemic and local functions. Activation of related hormone receptors and crosstalk with other signalling pathways are also key considerations.

Ki-67 and PCNA Expression in Canine Mammary Tumors and Adjacent Nonneoplastic Mammary Glands: Prognostic Impact by a Multivariate Survival Analysis

The assessment of tumor proliferation has been considered a determining prognostic factor in canine mammary tumors (CMTs). However, no studies have assessed the prognostic importance of proliferation in adjacent nonneoplastic mammary glands. We included 64 CMTs (21 benign and 43 malignant) and studied the proliferation index (PI) of Ki-67 and proliferating cell nuclear antigen (PCNA) together with several clinicopathological characteristics. A positive and statistically significant correlation between the PI of Ki-67 and PCNA in tumors and adjacent nonneoplastic mammary glands was observed in benign and malignant tumors. Tumor size, skin ulceration, histological type, mitotic index, nuclear grade, differentiation grade, histological grade of malignancy, lymph node metastasis, Ki-67, and PCNA expression in tumors and adjacent nonneoplastic mammary glands were statistically associated with overall survival by univariate analysis in malignant cases (n = 43). Histological grade of malignancy and high intratumoral PCNA retained their significance by multivariate analysis arising as independent predictors of overall survival. Interestingly, the PI of Ki-67 and PCNA of adjacent nontumoral mammary glands were associated with clinicopathological features of tumor aggressiveness and shorter overall survival, demonstrating the need to better explore this adjacent non-neoplastic tissue.

High COX-2 expression is associated with increased angiogenesis, proliferation and tumoural inflammatory infiltrate in canine malignant mammary tumours: a multivariate survival study

COX-2 expression affects mammary tumourigenesis by promoting angiogenesis and cell proliferation, encouraging metastatic spread and tumour-associated inflammation. Samples of canine mammary tumours (n = 109) were submitted to immunohistochemistry to detect COX-2, CD31, VEGF, Ki-67, CD3 and MAC387 expression. Concurrent high expression of COX-2/CD31, COX-2/VEGF, COX-2/Ki-67, COX-2/CD3 and COX-2/MAC was associated with elevated grade of malignancy, presence of intravascular emboli and presence of lymph node metastasis. Tumours with high COX-2 (P < 0.001) and tumours with concurrent expression of high COX-2 and high CD31 (P = 0.008); high VEGF (P < 0.001); high Ki-67 (P < 0.001); high CD3+ T-lymphocytes (P = 0.002) and elevated MAC387 macrophages (P = 0.024) were associated with shorter overall survival (OS) time. Interestingly the groups with high COX-2/CD31 and high COX-2/VEGF retained their significance after multivariate analysis arising as independent predictors of OS. Present data highlight the importance of COX-2 in canine mammary tumourigenesis.

Growth hormone and cancer: GH production and action in glioma?

The hypersecretion of pituitary growth hormone (GH) is associated with an increased risk of cancer, while reducing pituitary GH signaling reduces this risk. Roles for pituitary GH in cancer are therefore well established. The expression of the GH gene is, however, not confined to the pituitary gland and it is now known to occur in many extrapituitary tissues, in which it has local autocrine or paracrine actions, rather than endocrine function. It is, for instance, expressed in cancers of the prostate, lung, skin, endometrium and colon. The oncogenicity of autocrine GH may also be greater than that induced by endocrine or exogenous GH, as higher concentrations of GHR antagonists are required to inhibit its actions. This may reflect the fact that autocrine GH is thought to act at intracellular receptors directly after synthesis, in compartments not readily accessible to endocrine (or exogenous) GH. The roles and actions of extrapituitary GH in cancer may therefore differ from those of pituitary GH. The possibility that GH may be expressed and act in glioma tumors was therefore examined by immunohistochemistry. These results demonstrate, for the first time, the presence of abundant GH- and GH receptor (GHR-) immunoreactivity in glioma, in which they were co-localized in cytoplasmic but not nuclear compartments. These results demonstrate that glioma differs from most cancers in lacking nuclear GHRs, but GH is nevertheless likely to have autocrine or paracrine actions in the induction and progression of glioma.

Relationship among insulin resistance, growth hormone, and insulin-like growth factor I concentrations in diestrous Swedish Elkhounds

Background

In the dog, the normal estrous cycle includes a prolonged luteal phase. Progesterone stimulates local canine mammary growth hormone (GH) production, which may act systemically and contribute to insulin resistance. Swedish Elkhounds are predisposed to progesterone‐related diabetes mellitus, and the relationship among insulin resistance, GH, and insulin‐like growth factor I (IGF‐I) is of particular interest.

Objective

To study insulin resistance in relation to GH and IGF‐I in nondiabetic Swedish Elkhounds during diestrus. We also assessed whether alterations in these hormones could predict diestrus‐linked diseases and all‐cause mortality.

Animals

Eighty‐four privately owned female intact Swedish Elkhounds >4 years of age.

Methods

Blood sampling and clinical examination during luteal phase, with a follow‐up questionnaire after 20 months. Insulin resistance was calculated by homeostasis model assessment (HOMA‐IR).

Results

In multivariable regression analysis, GH was positively associated with HOMA‐IR (P = .009). An increase in GH of 1 ng/mL was associated with a 12.7% increase in HOMA‐IR. Moreover, C‐peptide was positively associated with IGF‐I (P = .04), and an increase in C‐peptide of 0.1 ng/mL was associated with a 6.9% increase in IGF‐I. Structural equation modeling supported these results. Twenty‐three animals were found to have previously unrecognized mammary masses and had higher GH (P < .0001) and IGF‐I (P = .007) than dogs without mammary masses (n = 61). There was no association between high GH and IGF‐I concentrations at sampling and future mammary masses.

Conclusion

We showed that GH was strongly associated with insulin resistance in older Swedish Elkhounds during diestrus.

Fasting Reduces the Incidence of Delayed-Type Vomiting Associated with Doxorubicin Treatment in Dogs with Lymphoma

Fasting reduces gastrointestinal cellular proliferation rates through G1 cycle blockade and can promote cellular protection of normal but not cancer cells through altered cell signaling including down-regulation of insulin-like growth factor 1 (IGF-1). Consequently, the purpose of this study was to determine the effects of fasting on delayed-type chemotherapy-induced nausea and vomiting in dogs receiving doxorubicin. This prospective randomized crossover study involved intended administration of two doses of doxorubicin. Cancer-bearing dogs were randomized to be fasted for 24 hours beginning at 6 P.M. the night before the first or second doxorubicin administration, and all treatments were administered within an hour before or after 12 P.M. Dogs were fed normally before the alternate dose. Circulating IGF-1 concentrations were determined from serum samples obtained immediately before each doxorubicin treatment. Data from 35 doses were available from 20 dogs enrolled. Dogs that were fasted exhibited a significantly lower incidence of vomiting, when compared to fed dogs (10% compared to 67%, P = .020). Furthermore, among the 15 dogs that completed crossover dosing, vomiting was abrogated in four of five dogs that experienced doxorubicin-induced vomiting when fed normally (P = .050). No differences in other gastrointestinal, constitutional, or bone marrow toxicities or serum IGF-1 levels were observed.

Canine mammary tumors: a review and consensus of standard guidelines on epithelial and myoepithelial phenotype markers, HER2, and hormone receptor assessment using immunohistochemistry

Although there have been several studies on the use of immunohistochemical biomarkers of canine mammary tumors (CMTs), the results are difficult to compare. This article provides guidelines on the most useful immunohistochemical markers to standardize their use and understand how outcomes are measured, thus ensuring reproducibility of results. We have reviewed the biomarkers of canine mammary epithelial and myoepithelial cells and identified those biomarkers that are most useful and those biomarkers for invasion and lymph node micrometastatic disease. A 10% threshold for positive reaction for most of these markers is recommended. Guidelines on immunolabeling for HER2, estrogen receptors (ERs), and progesterone receptors (PRs) are provided along with the specific recommendations for interpretation of the results for each of these biomarkers in CMTs. Only 3+ HER2-positive tumors should be considered positive, as found in human breast cancer. The lack of any known response to adjuvant endocrine therapy of ER- and PR-positive CMTs prevents the use of the biological positive/negative threshold used in human breast cancer. Immunohistochemistry results of ER and PR in CMTs should be reported as the sum of the percentage of positive cells and the intensity of immunolabeling (Allred score). Incorporation of these recommendations in future studies, either prospective or retrospective, will provide a mechanism for the direct comparison of studies and will help to determine whether these biomarkers have prognostic significance. Finally, these biomarkers may ascertain the most appropriate treatment(s) for canine malignant mammary neoplasms.

Growth hormone and cancer: an update on progress

PURPOSE OF REVIEW

Animals born with a deficiency in the cell surface receptor for growth hormone (GH) have a significantly reduced risk of developing cancer. Conversely, increased expression levels of GH and the GH receptor (GHR) are detectable in a variety of different human cancers. Here we discuss recent literature contributing to our understanding of the field.

RECENT FINDINGS

In addition to animal evidence, studies of individuals with Laron syndrome suggest that congenital GHR deficiency may also protect humans against cancer. GH expression in certain malignancies is correlated with clinicohistopathological parameters and may contribute the therapeutic resistance. Other recent studies have identified novel aspects of the GH signal transduction pathway, including receptor crosstalk and the involvement of microRNA in endocrine regulation of GH.

SUMMARY

Substantial evidence suggests the GH/insulin-like growth factor-1 axis initiates and promotes progression of cancer. However, important questions remain unanswered regarding the therapeutic utility of GH or GHR antagonism in cancer. Further clinical studies regarding the clinical association of GH expression with human malignancies and translational studies investigating GHR antagonism in animal models of human cancer are critical.

Relação da expressão de fatores de crescimento celular (IGF-1) e (SCF) com fatores prognósticos e o alvo da rapamicina em mamíferos (m-TOR) em mastocitomas cutâneos caninos

O mastocitoma cutâneo (MTC) é a neoplasia maligna mais comum na pele dos cães e seu comportamento biológico é muito variável. Dentre os fatores prognósticos estudados nos MTCs, a classificação histopatológica, o índice proliferativo e o padrão de expressão doc-KIT são os que apresentam uma associação mais relevante com o provável prognóstico deste tumor. O objetivo deste trabalho foi avaliar a expressão proteica de fator de crescimento semelhante à insulina tipo 1 (IGF-1), fator de célula tronco (SCF) e sua relação com o receptor tirosina quinase (c-KIT), alvo da rapamicina em mamíferos (m-TOR), grau histológico, índice proliferativo pelo KI-67e o número de figuras de mitose (IM) com dados clínicos de cães com MTCs . Foram utilizadas 133 amostras de MTCs, provenientes de 133 cães, dispostas em lâminas de microarranjo de tecidos (TMA). A técnica de imuno-histoquímica foi utilizada para a avaliação destas proteínas. Observou-se associação entre SCF e, a graduação histopatológica proposta em 2011, índice mitótico, proliferação celular (KI-67), escore de IGF-1, local da lesão, idade dos animais e padrão imuno-histoquímico do receptor c-KIT. A relação de dependência também foi observada entre IGF-1 e o porte dos animais, IM, m-TOR e c-KIT. A expressão de SCF teve relacção com a agressividade dos MTCs caninos, uma vez que foi mais freqüente em MTCs com c-KIT citoplasmático. A relação entre a expressão de IGF-1, SCF, c-KIT e m-TOR pode estar associada à integralização de suas vias de ação. A expressão de IGF-1 está associada à MTCs em cães de porte grande.

Tumor expression of human growth hormone and human prolactin predict a worse survival outcome in patients with mammary or endometrial carcinoma

CONTEXT

Evidence suggests that human GH (hGH) and human prolactin (hPRL) possess an autocrine or paracrine oncogenic role in mammary and endometrial carcinoma. However, especially for hGH, the prognostic relevance of tumor expression of these hormones is not well defined.

OBJECTIVE

We investigated the potential association of tumor mRNA and protein expression of hGH and hPRL with the clinicopathological features of mammary and endometrial carcinoma. The prognostic relevance of the individual or combined expression of hGH and hPRL in mammary and endometrial carcinoma was also determined.

DESIGN

The expression of hGH and hPRL was analyzed in histopathological samples of mammary and endometrial carcinoma, and the respective normal tissues, by in situ hybridization and immunohistochemistry. Kaplan-Meier and Cox regression analysis was performed to examine the association of tumor hGH and hPRL expression with relapse-free survival and overall survival of patients.

RESULTS

hGH expression was significantly associated with lymph node metastasis, tumor stage, human epidermal growth factor receptor-2 status, and proliferative index in mammary carcinoma and with International Federation of Gynecology and Obstetrics grade, myometrial invasion, and ovarian metastases in endometrial carcinoma. hPRL expression was associated with lymph node metastasis, tumor grade, and tumor stage in mammary carcinoma and with International Federation of Gynecology and Obstetrics stage and myometrial invasion in endometrial carcinoma. Both hGH and hPRL expression, individually and combined, are associated with worse relapse-free survival and overall survival in patients with mammary or endometrial carcinoma.

CONCLUSION

Tumor expression of both hGH or hPRL in mammary or endometrial carcinoma is associated with a large and significant difference in survival outcome for patients with these tumors.

Role of the growth hormone-IGF-1 axis in cancer

A substantial body of evidence supports a role for the growth hormone (GH)-IGF-1 axis in cancer incidence and progression. This includes epidemiological evidence relating elevated plasma IGF-1 to cancer incidence as well as a lack of cancers in GH/IGF-1 deficiency. Rodent models lacking GH or its receptor are strikingly resistant to the induction of a wide range of cancers, and treatment with the GH antagonist pegvisomant slows tumor progression. While GH receptor expression is elevated in many cancers, autocrine GH is present in several types, and overexpression of autocrine GH can induce cell transformation. While the mechanism of autocrine action is not clear, it does involve both STAT5 and STAT3 activation, and probably nuclear translocation of the GH receptor. Development of a more potent GH receptor antagonist or secretion inhibitor is warranted for cancer therapy.