Erythropoietin in thyroid cancer

Papillary Thyroid Carcinoma: A thorough Bioinformatic Analysis of Gene Expression and Clinical Data

The likelihood of being diagnosed with thyroid cancer has increased in recent years; it is the fastest-expanding cancer in the United States and it has tripled in the last three decades. In particular, Papillary Thyroid Carcinoma (PTC) is the most common type of cancer affecting the thyroid. It is a slow-growing cancer and, thus, it can usually be cured. However, given the worrying increase in the diagnosis of this type of cancer, the discovery of new genetic markers for accurate treatment and prognostic is crucial. In the present study, the aim is to identify putative genes that may be specifically relevant in PTC through bioinformatic analysis of several gene expression public datasets and clinical information. Two datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) dataset were studied. Statistics and machine learning methods were sequentially employed to retrieve a final small cluster of genes of interest: PTGFR, ZMAT3, GABRB2, and DPP6. Kaplan-Meier plots were employed to assess the expression levels regarding overall survival and relapse-free survival. Furthermore, a manual bibliographic search for each gene was carried out, and a Protein-Protein Interaction (PPI) network was built to verify existing associations among them, followed by a new enrichment analysis. The results revealed that all the genes are highly relevant in the context of thyroid cancer and, more particularly interesting, PTGFR and DPP6 have not yet been associated with the disease up to date, thus making them worthy of further investigation as to their relationship to PTC.

Erythropoietin and co.: intrinsic structure and functional disorder

Erythropoietin (Epo) is a heavily glycosylated protein, with its main function being related to erythropoiesis, where it controls red blood cell production via interaction with the Epo receptor (EpoR). It also plays a number of important roles in various hormonal, growth factor, and cytokine pathways. These roles are defined by Epo partners, such as the homodimeric (EpoR)2 receptor, the heterodimeric EpoR/βCR receptor and hypoxia inducing factor (HIF). Although the main structural features of both Epo and EpoR are conserved in vertebrates, the secretion sites of Epo in mammals are different from those in other vertebrates. Both biosynthetic and synthetic analogues of this protein are available on the market. Several side effects, such as pure red cells aplaisa, increase the rate of cancer-related death in patients treated with recombinant Epo. The multifunctionality of Epo and the ability of this protein to serve as a hormone, a cytokine, and a growth factor suggest the presence of functional disorder, which is a typical "structural" feature of moonlighting proteins. The goal of this article is to evaluate the roles of intrinsic disorder in the functions of Epo and its primary interactors, EpoR, βCR, and HIF-1α.

(131)I treatment in Differentiated Thyroid Cancer and End-Stage Renal Disease

PURPOSE

Radioiodine (RAI) is a cornerstone in the treatment of Differentiated Thyroid Cancer (DTC). In patients on haemodialysis due to End-Stage Renal Disease (ESRD), it must be used cautiously, considering the renal clearance of this radionuclide. Also, the safety of the procedure and subsequent long-term outcome is still not well defined. In 2001, we described a dosimetric method and short-term results in three patients, with a good safety profile. We hypothesize that our method is safe in a long-term scenario without compromising the prognosis of both renal and thyroid disease.

MATERIAL AND METHODS

Descriptive-retrospective study. A systematic search was carried out using our clinical database from 2000 to 2014.

INCLUSION CRITERIA

DTC and radioiodine treatment while on haemodialysis.

EXCLUSION CRITERIA

peritoneal dialysis.

RESULTS

Final sample n=9 patients (n=5 males), age 48 years (median age 51 years males, 67 years female group); n=8 papillary thyroid cancer, n=1 follicular thyroid cancer; n=5 lymph node invasion; n=1 metastatic disease. Median RAI dose administered on haemodialysis 100mCi. 7.5 years after radioiodine treatment on haemodialysis, n=7 deemed free of thyroid disease, n=1 persistent non-localised disease. No complications related to the procedure or other target organs were registered. After 3.25 years, n=4 patients underwent successful renal transplantation; n=4 patients did not meet transplantation criteria due to other conditions unrelated to the thyroid disease or its treatment. One patient died due to ischemic cardiomyopathy (free of thyroid disease).

CONCLUSIONS

Radioiodine treatment during haemodialysis is a long-term, safe procedure without worsening prognosis of either renal or thyroid disease.

Thyroid regeneration: characterization of clear cells after partial thyroidectomy

Although having the capacity to grow in response to a stimulus that perturbs the pituitary-thyroid axis, the thyroid gland is considered not a regenerative organ. In this study, partial thyroidectomy (PTx) was used to produce a condition for thyroid regeneration. In the intact thyroid gland, the central areas of both lobes served as the proliferative centers where microfollicles, and bromodeoxyuridine (BrdU)-positive and/or C cells, were localized. Two weeks after PTx, the number of BrdU-positive cells and cells with clear or faintly eosinophilic cytoplasm were markedly increased in the central area and continuous to the cut edge. Clear cells were scant in the cytoplasm, as determined by electron microscopy; some retained the characteristics of calcitonin-producing C cells by having neuroendocrine granules, whereas others retained follicular cell-specific features, such as the juxtaposition to a lumen with microvilli. Some cells were BrdU-positive and expressed Foxa2, the definitive endoderm lineage marker. Serum TSH levels drastically changed due to the thyroidectomy-induced acute reduction in T(4)-generating tissue, resulting in a goitrogenesis setting. Microarray followed by pathway analysis revealed that the expression of genes involved in embryonic development and cancer was affected by PTx. The results suggest that both C cells and follicular cells may be altered by PTx to become immature cells or immature cells that might be derived from stem/progenitor cells on their way to differentiation into C cells or follicular cells. These immature clear cells may participate in the repair and/or regeneration of the thyroid gland.

Erythropoietin receptor contributes to melanoma cell survival in vivo

Erythropoietin (Epo) is widely used clinically to treat anemia associated with various clinical conditions including cancer. Data from several clinical trials suggest significant adverse effect of Epo treatment on cancer patient survival. However, controversy exists whether Epo receptor (EpoR) is functional in cancer cells. In this study, we demonstrated that EpoR mRNA expression was detectable in 90.1% of 65 melanoma cell lines, and increased copy number of the Epo and EpoR loci occurred in 30 and 24.6% of 130 primary melanomas, respectively. EpoR knockdown in melanoma cells resulted in diminished ERK phosphorylation in response to Epo stimulation, decreased cell proliferation and increased response to the inhibitory effect of hypoxia and cisplatin in vitro. EpoR knockdown significantly decreased melanoma xenograft size and tumor invasion in vivo. On the contrary, constitutive activation of EpoR activated cell proliferation pathways in melanoma cells and resulted in increased cell proliferation and resistance to hypoxia and cisplatin treatment in vitro. EpoR activation resulted in significantly larger xenografts with increased tumor invasion of surrounding tissue in vivo. Daily administration of recombinant Epo fails to stimulate melanoma growth in vivo, but the treatment increased vascular size in the xenografts. Increased local recurrence after excision of the primary tumors was observed after Epo treatment. Epo induced angiogenesis in Matrigel plug assays, and neutralization of Epo secreted by melanoma cells results in decreased angiogenesis. These data support that EpoR is functional in melanoma and EpoR activation may promote melanoma progression, and suggest that Epo may stimulate angiogenesis and increase survival of melanoma cells under hypoxic condition in vivo.

Prognostic impact of erythropoietin expression and erythropoietin receptor expression on locoregional control and survival of patients irradiated for stage II/III non-small-cell lung cancer

PURPOSE

Prognostic factors can guide the physician in selecting the optimal treatment for an individual patient. This study investigates the prognostic value of erythropoietin (EPO) and EPO receptor (EPO-R) expression of tumor cells for locoregional control and survival in non-small-cell lung cancer (NSCLC) patients.

METHODS AND MATERIALS

Fourteen factors were investigated in 62 patients irradiated for stage II/III NSCLC, as follows: age, gender, Karnofsky performance score (KPS), histology, grading, TNM/American Joint Committee on Cancer (AJCC) stage, surgery, chemotherapy, pack years (average number of packages of cigarettes smoked per day multiplied by the number of years smoked), smoking during radiotherapy, hemoglobin levels during radiotherapy, EPO expression, and EPO-R expression. Additionally, patients with tumors expressing both EPO and EPO-R were compared to those expressing either EPO or EPO-R and to those expressing neither EPO nor EPO-R.

RESULTS

On univariate analysis, improved locoregional control was associated with AJCC stage II cancer (p < 0.048), surgery (p < 0.042), no smoking during radiotherapy (p = 0.024), and no EPO expression (p = 0.001). A trend was observed for a KPS of >70 (p = 0.08), an N stage of 0 to 1 (p = 0.07), and no EPO-R expression (p = 0.10). On multivariate analysis, AJCC stage II and no EPO expression remained significant. No smoking during radiotherapy was almost significant. On univariate analysis, improved survival was associated with N stage 0 to 1 (p = 0.009), surgery (p = 0.039), hemoglobin levels of ≥12 g/d (p = 0.016), and no EPO expression (p = 0.001). On multivariate analysis, N stage 0 to 1 and no EPO expression maintained significance. Hemoglobin levels of ≥12 g/d were almost significant. On subgroup analyses, patients with tumors expressing both EPO and EPO-R had worse outcomes than those expressing either EPO or EPO-R and those expressing neither EPO nor RPO-R.

CONCLUSIONS

EPO expression of tumor cells was an independent prognostic factor for locoregional control and survival in patients irradiated for NSCLC. EPO-R expression showed a trend. Patients with tumors expressing both EPO and EPO-R have an unfavorable prognosis.

The erythropoietin receptor in normal and cancer tissues

The hormone erythropoietin (EPO) is essential for the survival, proliferation and differentiation of the erythrocytic progenitors. The EPO receptor (EPO-R) of erythrocytic cells belongs to the cytokine class I receptor family and signals through various protein kinases and STAT transcription factors. The EPO-R is also expressed in many organs outside the bone marrow, suggesting that EPO is a pleiotropic anti-apoptotic factor. The controversial issue as to whether the EPO-R is functional in tumor tissue is critically reviewed. Importantly, most studies of EPO-R detection in tumor tissue have provided falsely positive results because of the lack of EPO-R specific antibodies. However, endogenous EPO appears to be necessary to maintain the viability of endothelial cells and to promote tumor angiogenesis. Although there is no clinical proof that the administration of erythropoiesis stimulating agents (ESAs) promotes tumor growth and mortality, present recommendations are that (i) ESAs should be administered at the lowest dose sufficient to avoid the need for red blood cell transfusions, (ii) ESAs should not be used in patients with active malignant disease not receiving chemotherapy or radiotherapy, (iii) ESAs should be discontinued following the completion of a chemotherapy course, (iv) the target Hb should be 12 g/dL and not higher and (v) the risks of shortened survival and tumor progression have not been excluded when ESAs are dosed to target Hb <12 g/dL.

Protein kinase A-independent inhibition of proliferation and induction of apoptosis in human thyroid cancer cells by 8-Cl-adenosine

PURPOSE

Protein kinase A (PKA) affects cell proliferation in many cell types and is a potential target for cancer treatment. PKA activity is stimulated by cAMP and cAMP analogs. One such substance, 8-Cl-cAMP, and its metabolite 8-Cl-adenosine (8-Cl-ADO) are known inhibitors of cancer cell proliferation; however, their mechanism of action is controversial. We have investigated the antiproliferative effects of 8-Cl-cAMP and 8-CL-ADO on human thyroid cancer cells and determined PKA's involvement.

EXPERIMENTAL DESIGN

We employed proliferation and apoptosis assays and PKA activity and cell cycle analysis to understand the effect of 8-Cl-ADO and 8-Cl-cAMP on human thyroid cancer and HeLa cell lines.

RESULTS

8-Cl-ADO inhibited proliferation of all cells, an effect that lasted for at least 4 d. Proliferation was also inhibited by 8-Cl-cAMP, but this inhibition was reduced by 3-isobutyl-1-methylxanthine; both drugs stimulated apoptosis, and 3-isobutyl-1-methylxanthine drastically reduced 8-Cl-cAMP-induced cell death. 8-Cl-ADO induced cell accumulation in G1/S or G2/M cell cycle phases and differentially altered PKA activity and subunit levels. PKA stimulation or inhibition and adenosine receptor agonists or antagonists did not significantly affect proliferation.

CONCLUSIONS

8-Cl-ADO and 8-Cl-cAMP inhibit proliferation, induce cell cycle phase accumulation, and stimulate apoptosis in thyroid cancer cells. The effect of 8-Cl-cAMP is likely due to its metabolite 8-Cl-ADO, and PKA does not appear to have direct involvement in the inhibition of proliferation by 8-Cl-ADO. 8-Cl-ADO may be a useful therapeutic agent to be explored in aggressive thyroid cancer.

Erythropoietin and erythropoietin receptor coexpression is associated with poor survival in stage I non-small cell lung cancer

PURPOSE

This study was designed to evaluate the prognostic effect of erythropoietin (EPO) and EPO receptor (EPO-R) expression in stage I non-small cell lung cancer (NSCLC) patients.

EXPERIMENTAL DESIGN

EPO and EPO-R expression in 158 tumor samples from resected stage I NSCLC was evaluated using immunohistochemistry and tissue array technology.

RESULTS

EPO-R and EPO were highly expressed in 20.9% and 35.4% of tumors, respectively. High EPO-R expression compared with negative or low-level expression was associated with a poor 5-year disease-specific survival (60.6% versus 80.8%; P = 0.01, log-rank test). High EPO expression compared with negative and low-level expression was associated with a trend toward a poor 5-year disease-specific survival (69.6% versus 80.4%; P = 0.13, log-rank test). A high level of EPO-R and EPO coexpression was associated with a poor 5-year disease-specific survival compared with other groups of patients (50.0% versus 80.0% survival at the end of follow-up; P = 0.005, log-rank test). In multivariate analysis for disease-specific survival, high-level EPO-R and EPO coexpression was an independent prognostic factor for disease-specific survival (hazard ratio, 2.214; 95% confidence interval, 1.012-4.848; P = 0.046).

CONCLUSION

These results establish the pejorative prognostic value of EPO and EPO-R expression in early-stage resected NSCLC and suggest a potential paracrine and/or autocrine role of endogenous EPO in NSCLC aggressiveness.

Thyroid cancer in children

In 1996, the authors were asked to review the subject of thyroid cancer in children. Over the subsequent decade, much has been learned about the treatment and outcome of these uncommon tumors. We now recognize quantitative and perhaps qualitative differences in genetic mutations and growth factor expression patterns in childhood thyroid cancers compared with those of adults. We also know that thyroid cancers induce a robust immune response in children that might contribute to their longevity. Patients under 10 years of age probably represent a unique subset of children at particularly high risk for persistent or recurrent disease; the management of these patients is under evaluation. We remain limited in our knowledge of how to stratify children into low- and high-risk categories for appropriate long-term follow-up and in our knowledge of how to treat children who have detectable serum thyroglobulin but negative imaging studies. In this article, the authors update our understanding of thyroid cancers in children with special emphasis on how these data relate to the current guidelines for management of thyroid cancer developed by the American Thyroid Association Taskforce. The limited data regarding management of children who have detectable serum thyroglobulin but negative whole-body scans are also reviewed.