Immunohistochemical and molecular pattern of p53 in epithelial ovarian cancers negative for germline BRCA1/2 variants

Epithelial ovarian cancers (EOC) associated with germline or somatic BRCA pathogenetic variants have a significantly higher rate of TP53aberrations. The majority of TP53 mutations are detectable by immunohistochemistry and several studies demonstrated that an abnormal p53 pattern characterized high-grade EOCs. An abnormal p53 immunohistochemical staining in fallopian tube (serous tubal intraepithelial carcinoma (STIC) and "p53 signature" is considered as a precancerous lesion of high-grade EOCs and it is often found in fallopian tube tissues of BRCA germline mutated patients suggesting that STIC is an early lesion and the TP53 mutation is an early driver event of BRCA mutated high-grade EOCs. No relevant data are present in literature about the involvement of p53 abnormal pattern in EOC carcinogenesis of patients negative for germline BRCA variants. We describe TP53 mutation results in relationship to the immunohistochemical pattern of p53 expression in a series of EOCs negative for BRCA1 and BRCA2 germline mutations. In addition, we also investigated STIC presence and "p53 signature" in fallopian tube sampling of these EOCs. Our results demonstrate that TP53 alterations are frequent and early events in sporadic EOCs including also low-grade carcinomas. Also in this series, STIC is associated with an abnormal p53 pattern in fallopian tubes of high-grade EOCs. In summary, TP53 aberrations are the most frequent and early molecular events in EOC carcinogenesis independently from BRCA mutation status.

Host nasopharyngeal transcriptome dataset of a SARS-CoV-2 positive Italian cohort

The ongoing COVID-19 pandemic caused by SARS-CoV-2 has affected millions of people worldwide and has significant implications for public health. Host transcriptomics profiling provides comprehensive understanding of how the virus interacts with host cells and how the host responds to the virus. COVID-19 disease alters the host transcriptome, affecting cellular pathways and key molecular functions. To contribute to the global effort to understand the virus's effect on host cell transcriptome, we have generated a dataset from nasopharyngeal swabs of 35 individuals infected with SARS-CoV-2 from the Campania region in Italy during the three outbreaks, with different clinical conditions. This dataset will help to elucidate the complex interactions among genes and can be useful in the development of effective therapeutic pathways.

Combinatorial targeting of menin and the histone methyltransferase DOT1L as a novel therapeutic strategy for treatment of chemotherapy-resistant ovarian cancer

Background

Ovarian cancer (OC) is characterized by a low response rate and high frequency of resistance development to currently available treatments. The therapeutic potential of histone methyltransferase DOT1L inhibitor in OC cells has been demonstrated, but optimal efficacy and safety of this targeted therapy approach still require improvement. We set forth to evaluate if this problem can be overcome by combinatorial targeting of this epigenetic modifier and menin, one of its functional partners in chromatin.

Methods

siRNA-mediated gene knock-down and pharmacological inhibition of menin, a key component of the MLL/SET1 complex and a fitness gene in OC cells, coupled to cell proliferation assays on a panel of high grade serous OC cell lines, including chemotherapy-sensitive and -resistant clones, were applied in order to evaluate how depletion or blockade of this enzyme influences growth and viability of OC cells. RNA sequencing was applied to identify menin target genes and pathways, and the effects of combined inhibition of menin and DOT1L on growth and transcriptome of these OC models were evaluated.

Results

Silencing and pharmacological inhibition of menin exert antiproliferative effects in all OC cells tested and, in PEO1 and PEO4 cells, a profound impact on transcriptome via down-regulation of cell cycle regulatory pathways, aryl hydrocarbon receptor, MYC and KRAS signalling. We demonstrated association of menin and DOT1L in OC cells and identified a subset of genes co-regulated by the two factors. Interestingly, co-treatment with DOT1L and menin pharmacological inhibitors exerts an additive effect on growth inhibition on chemotherapy-sensitive and -refractory OC cells mediated by transcriptome changes controlled by menin and DOT1L activities.

Conclusion

These results indicate that menin functionally cooperates with DOT1L in OC cells modulating transcription of genes involved in key cellular functions including, among others, cell proliferation and survival, that are strongly affected by combined inhibition of these two epigenetic regulators, suggesting that this may represent a novel therapeutic strategy for chemotherapy-resistant OCs.

Trial registration

NA; The manuscript does not contain clinical trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02740-6.

Dynamics of nasopharyngeal tract phageome and association with disease severity and age of patients during three waves of COVID-19

In December 2019, several patients were hospitalized and diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which subsequently led to a global pandemic. To date, there are no studies evaluating the relationship between the respiratory phageome and the SARS-CoV-2 infection. The current study investigated the phageome profiles in the nasopharyngeal swabs collected from 55 patients during the three different waves of coronavirus disease 2019 (COVID-19) in the Campania Region (Southern Italy). Data obtained from the taxonomic profiling show that phage families belonging to the order Caudovirales have a high abundance in the patient samples. Moreover, the severity of the COVID-19 infection seems to be correlated with the phage abundance.

Targeted molecular profiling of epithelial ovarian cancer from Italian BRCA wild-type patients with a BRCA and PARP pathways gene panel

Ovarian cancer (OC) is the fifth most common type of cancer in women and the fourth most common cause of cancer death in women. Identification of pathogenic variants in OC tissues has an important clinical significance for therapeutic and prevention purposes. This study aims to evaluate the mutational profile of a patient cohort, negative for BRCA1/2 germinal variants and Mismatch Repair defects, using next-generation sequencing (NGS) approach on DNA from formalin-fixed paraffin-embedded samples. We used a custom NGS panel, targeting 34 cancer-related genes, mainly of the BRCA and PARP pathways, and analyzed NGS data to identify somatic and germline variants in Italian patients affected by primary epithelial ovarian cancer. We analyzed 75 epithelial ovarian cancer tissues and identified 54 pathogenic variants and 56 variants of unknown significance. TP53 was characterized by the highest mutational rate, occurring in 55% of tested epithelial ovarian cancers (EOCs). Interestingly, a subset of 8 EOCs showed pathogenic variants of homologous recombination pathway, which could be sensitive to PARP-inhibitor therapies. Germline analysis of actionable genes revealed 4 patients carrier of pathogenic germline variants respectively of RAD51C (2 patients), RAD51D, and PALB2. Molecular profiling of EOCs using our custom NGS panel has enabled the detection of both somatic and germline variants, allowing the selection of patients suitable for targeted therapies, and the identification of high-risk OC families that can benefit from genetic counseling and testing.

AB0853 The role of IL-17, IL-23 serum levels in patients with ankylosing spondylitis with inflammatory bowel diseases

Background

Currently, there is a lot of interest in the frequency and risks of developing of inflammatory bowel diseases (IBD) in patients with ankylosing spondylitis (AS) [1]. IL-17 and IL-23 are one of the key pathogenetic markers of AS [2]. A lot of studies also showed that the average number of IL-17 cells was significantly increased in active Ulcerative colitis (UC) and Crohn disease (CD) patients [3]. According to some studies cytokines, such as IL-17 and IL-23, play crucial role in intestinal protection and homeostasis [4].

Objectives

The aim of this study was to evaluate IL-17 and IL-23 serum levels in patients with AS without IBD and with AS and IBD.

Methods

In the analysis were included 50 patients with AS, fulfilling the modified New York criteria, among them man-36 (72%), woman-14 (28%), mean age of patients was 42.5±9.9, mean disease duration – 13.4±8.7 years. All patients were examined with ESR, CRP, esophagogastroduodenoscopy, colonoscopy, IL-17 and IL-23, using enzyme-linked immunosorbent assay for the quantitative measurement of IL-17 and IL-23 in serum ELISA kit. IL-17 and IL-23 levels were also studied in control group (13 healthy donors), mean IL-17 was 1.16±1.02 pg/mL, mean IL-23 was 33.03±18.02 pg/mL.

Results

All patients had a high disease activity, mean BASDAI was 5.3± 1.8, mean ASDAS CRP 3.7±1.01, mean ASDAS ESR 3.6±1.01. IBD were diagnosed in 11 cases: 6 patients (12%) with CD and 5 patients (10%) - UC, in the remaining cases (78%-39 patients) was no intestinal pathology. Patiens with AS had higher levels of IL-17(10.4±9.1 pg/ml) and IL-23(188±156 pg/ml), than the group of healthy donors. Patients with AS and IBD had slightly lower IL-17(6.7±4.5 pg/ml) and IL-23(155.5±97 pg/ml) levels than patients with AS without IBD(p=0.03). IL-23 was positively correlated with ESR (r=0.5) and CRP (r=0.5) (p <0.001) levels, however IL-17 level had negative correlation with ESR and CRP level (r=-0.2) (p<0.001).

Conclusion

IL-23 and IL 17 serum levels in patients with AS and IBD was lower than in patients with AS without IBD. There is a significant association between the CRP, ESR and IL-23 level, but not with IL-17.

References

[1]Lukina G.V., Kulakova P.I., Novikov A.A., Savenkova N.A., Alexandrova E.A., Volnukhin E.V., Kovshik A.N. Frequency of inflammatory bowel diseases in patients with ankylosing spondylitis. Medical alphabet. 2019;2(37):12-15. https://doi.org/10.33667/2078-5631-2019-2-37(412)-12-15.

[2]Sherlock JP, Taylor PC, Buckley CD. The biology of IL-23 and IL-17 and their therapeutic targeting in rheumatic diseases. Curr Opin Rheumatol. 2015 Jan;27(1):71-5.doi:10.1097/BOR.0000000000000132.

[3]Fujino S, Andoh A, Bamba S, et al. Increased expression of interleukin 17 in inflammatory bowel diseases. Gut.2003;52:65-70.

[4]Shen W, Durum SK. Synergy of IL-23 and Th17 cytokines: new light on inflammatory bowel disease. Neurochem Res. 2010 Jun;35(6):940-6. doi: 10.1007/s11064-009-0091-9

Disclosure of Interests

None declared

Histone Methyltransferase DOT1L as a Promising Epigenetic Target for Treatment of Solid Tumors

The histone lysine methyltransferase DOT1L (DOT1-like histone lysine methyltransferase) is responsible for the epigenetic regulation of gene expression through specific methylation of lysine79 residue of histone H3 (H3K79) in actively transcribed genes. Its normal activity is crucial for embryonic development and adult tissues functions, whereas its aberrant functioning is known to contribute to leukemogenesis. DOT1L is the only lysine methyltransferase that does not contain a SET domain, which is a feature that allowed the development of selective DOT1L inhibitors that are currently investigated in Phase I clinical trials for cancer treatment. Recently, abnormal expression of this enzyme has been associated with poor survival and increased aggressiveness of several solid tumors. In this review evidences of aberrant DOT1L expression and activity in breast, ovarian, prostate, colon, and other solid tumors, and its relationships with biological and clinical behavior of the disease and response to therapies, are summarized. Current knowledge of the structural basis of DOT1L ability to regulate cell proliferation, invasion, plasticity and stemness, cell cycle progression, cell-to-cell signaling, epithelial-to-mesenchymal transition, and chemoresistance, through cooperation with several molecular partners including noncoding RNAs, is also reviewed. Finally, available options for the treatment of therapeutically challenging solid tumors by targeting DOT1L are discussed.

Nasopharyngeal virome analysis of COVID-19 patients during three different waves in Campania region of Italy

From December 2019, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection has spread rapidly, leading to a global pandemic. Little is known about possible relationships between SARS‐CoV‐2 and other viruses in the respiratory system affecting patient prognosis and outcomes. This study aims to characterize respiratory virome profiles in association with SARS‐CoV‐2 infection and disease severity, through the analysis in 89 nasopharyngeal swabs collected in a patient's cohort from the Campania region (Southern Italy). Results show coinfections with viral species belonging to Coronaviridae, Retroviridae, Herpesviridae, Poxviridae, Pneumoviridae, Pandoraviridae, and Anelloviridae families and only 2% of the cases (2/89) identified respiratory viruses.

•

The severe acute respiratory syndrome coronavirus 2 infection is considered a major global threat that is still spreading around the world.

•

Nasopharyngeal swabs samples were collected from the Campania region cohort of 89 Covid‐19 patients.

•

Descriptive analysis of respiratory virome was carried out with the HOME‐BIO pipeline, that performed viral taxonomy profiling.

•

It detected coinfections with viral species belonging to Coronaviridae, Retroviridae, Herpesviridae, Poxviridae, Pneumoviridae, Pandoraviridae, and Anelloviridae family.

•

Only 2% of the cases (2/89) identified respiratory viruses.

Rapid and sensitive detection of SARS-CoV-2 variants in nasopharyngeal swabs and wastewaters

The SARS-CoV-2 virus is continuously evolving, with appearance of new variants characterized by multiple genomic mutations, some of which can affect functional properties, including infectivity, interactions with host immunity, and disease severity. The rapid spread of new SARS-CoV-2 variants has highlighted the urgency to trace the virus evolution, to help limit its diffusion, and to assess effectiveness of containment strategies. We propose here a PCR-based rapid, sensitive and low-cost allelic discrimination assay panel for the identification of SARS-CoV-2 genotypes, useful for detection in different sample types, such as nasopharyngeal swabs and wastewater. The tests carried out demonstrate that this in-house assay, whose results were confirmed by SARS-CoV-2 whole-genome sequencing, can detect variations in up to 10 viral genome positions at once and is specific and highly sensitive for identification of all tested SARS-CoV-2 clades, even in the case of samples very diluted and of poor quality, particularly difficult to analyze.

POS1008 THE ROLE OF SERUM CALPROTECTIN IN THE DIAGNOSIS OF INFLAMMATORY BOWEL DISEASE IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Аnkylosing spondylitis (AS) and inflammatory bowel diseases (IBD) have many common features. Approximately one in two patients with axial spondyloarthritis have subclinical (histologically confirmed) inflammation of the intestine, and 5-10% of subclinical inflammation turns into Crohn’s disease (CD) or Ulcerative colitis (UC) [1]. Colonoscopy is usually used to diagnose IBD, but this procedure is invasive. Laboratory biomarkers, as fecal calprotectin (FC) and serum calprotectin (SC) can used to diagnosis of IBD. But there is no consensus regarding SC clinical utility. SC is exposed to proteolytic enzymes, but its level also increases with inflammation in the intestine and is associated with a higher disease activity [2]. SC levels positively correlate with CRP, ESR, disease activity in AS, but not as obvious as with FC [3,4].

Objectives:

The aim of this study was to evaluate the possibility of using SC in the diagnosis of IBD in patients with AS.

Methods:

In the analysis were included 50 patients with AS, fulfilling the modified New York criteria, among them man -36 (72%), woman -14 (28%), mean age of patients was 42.5 ±9.9, mean disease duration – 13.4±8.7 years. All patients were examined with ESR, CRP, FC (range: 100-1800 µg /g), esophagogastroduodenoscopy, colonoscopy and quantitative analysis of the SC level using ELISA (BUHLMANN MRP8/14 ELISA, range: 0.4-3.9 µg /ml).

Results:

All patients had a high disease activity, mean BASDAI was 5.3 ± 1.8, mean ASDAS CRP 3.7 ± 1.01, mean ASDAS ESR 3.6 ± 1.01. 80 % patients had high FC level (more than 100 µg / g), while only 18% patients had an increase of SC level. IBD were diagnosed in 11 cases: 6 patients (12 %) with CD and 5 patients (10 %) - UC, in the remaining cases (78%) was no intestinal pathology. Only 2 patients with IBD had a high SC level. SC level was more correlated with ESR (r=0.5) and CRP (r=0.5) (p <0.05) levels, than with FC level (r=0.4) (p <0.05).

Conclusion:

The results showed that there is currently insufficient data to assess the possibility of using SC in the diagnosis of IBD in patients with AS. There is a significant association between the SC, CRP and ESR, but not fecal calprotectin. Potentially SC may be more representative of systemic inflammation than an intestinal inflammation.

References:

[1]Klingberg, E., Strid, H., Stahl, A.et al. A longitudinal study of fecal calprotectin and the development of inflammatory bowel disease in ankylosing spondylitis. A longitudinal study of fecal calprotectin and the development of inflammatory bowel disease in ankylosing spondylitis. Arthritis Res Ther 2017. 19(1):21

[2]Kalla R, Kennedy NA, Ventham NT, Boyapati RK, Adams AT, Nimmo ER, Visconti MR, Drummond H, Ho GT, Pattenden RJ, Wilson DC, Satsangi J. Serum Calprotectin: A Novel Diagnostic and Prognostic Marker in Inflammatory Bowel Diseases. Am J Gastroenterol. 2016 Dec;111(12):1796-1805

[3]Hu H, Du F, Zhang S, Zhang W. Serum calprotectin correlates with risk and disease severity of ankylosing spondylitis and its change during first month might predict favorable response to treatment. Mod Rheumatol. 2019 Sep;29(5):836-842.

[4]Azramezani Kopi T, Shahrokh S, Mirzaei S, Asadzadeh Aghdaei H, Amini Kadijani A. The role of serum calprotectin as a novel biomarker in inflammatory bowel diseases: a review study. Gastroenterol Hepatol Bed Bench. 2019;12(3):183-189.

Disclosure of Interests:

None declared.

Insights into the Role of Estrogen Receptor β in Triple-Negative Breast Cancer

Estrogen receptors (ERα and ERβ) are ligand-activated transcription factors that play different roles in gene regulation and show both overlapping and specific tissue distribution patterns. ERβ, contrary to the oncogenic ERα, has been shown to act as an oncosuppressor in several instances. However, while the tumor-promoting actions of ERα are well-known, the exact role of ERβ in carcinogenesis and tumor progression is not yet fully understood. Indeed, to date, highly variable and even opposite effects have been ascribed to ERβ in cancer, including for example both proliferative and growth-inhibitory actions. Recently ERβ has been proposed as a potential target for cancer therapy, since it is expressed in a variety of breast cancers (BCs), including triple-negative ones (TNBCs). Because of the dependence of TNBCs on active cellular signaling, numerous studies have attempted to unravel the mechanism(s) behind ERβ-regulated gene expression programs but the scenario has not been fully revealed. We comprehensively reviewed the current state of knowledge concerning ERβ role in TNBC biology, focusing on the different signaling pathways and cellular processes regulated by this transcription factor, as they could be useful in identifying new diagnostic and therapeutic approaches for TNBC.

An Overview of Candidate Therapeutic Target Genes in Ovarian Cancer

Ovarian cancer (OC) shows the highest mortality rate among gynecological malignancies and, because of the absence of specific symptoms, it is frequently diagnosed at an advanced stage, mainly due to the lack of specific and early biomarkers, such as those based on cancer molecular signature identification. Indeed, although significant progress has been made toward improving the clinical outcome of other cancers, rates of mortality for OC are essentially unchanged since 1980, suggesting the need of new approaches to identify and characterize the molecular mechanisms underlying pathogenesis and progression of these malignancies. In addition, due to the low response rate and the high frequency of resistance to current treatments, emerging therapeutic strategies against OC focus on targeting single factors and pathways specifically involved in tumor growth and metastasis. To date, loss-of-function screenings are extensively applied to identify key drug targets in cancer, seeking for more effective, disease-tailored treatments to overcome lack of response or resistance to current therapies. We review here the information relative to essential genes and functional pathways recently discovered in OC, often strictly interconnected with each other and representing promising biomarkers and molecular targets to treat these malignancies.

AB0702 THE FREQUENCY OF INFLAMMATORY BOWEL DISEASES IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Аnkylosing Spondylitis (AS) is closely associated with inflammatory bowel disease (IBD). About 6-46% of patients with IBD have various lesions of the musculoskeletal system [1]. 5-10% of patients with spondylarthritis (SpA) eventually develop IBD, with Crohn’s disease (CD) being more common than Ulcerative colitis (UC) [2]. Determining the level of fecal calprotectin (FC) is a study that allows to diagnose IBD. The concentration of FC directly depends on the neutrophil infiltration of the intestinal mucosa and has a direct connection with the activity of the inflammatory process [3]. It is known that level of FC increases in 2/3 of patients with AS and is closely related to parameters reflecting higher disease activity [4].

Objectives:

The aim of this study was to evaluate the frequency of IBD in patients with AS using an assessment of FC level.

Methods:

In the analysis were included 40 patients with AS, fulfilling the modified New York criteria, among them man -26 (65%), woman -14 (35%), mean age of patients was 41.2 ±10.5, mean disease duration - 13±8.8 years. All patients were examined with ESR, CRP, esophagogastroduodenoscopy, colonoscopy and quantitative analysis of the fecal calprotectin levels using the method of lateral immunochromatography with the BUHLMANN Quantum Blue rapid test. Standart range: 100-1800 µg /g.

Results:

All patients had a high disease activity, mean BASDAI was 5.2 ± 1.7, mean ASDAS CRP 3.8 ± 1.1. 35 patients (87.5 %) had FC level more than 100 µg / g, the remaining 5 patients (12.5%) less than 100 µg /g. 12 patients (30 %) had FC level more than 1,800 µg / g, 23 (57.5 %) from 101 µg / g to 1800 µg / g. All patients with FC levels more than 100 µg / g showed an increase CRP (mean 28.4 mg / l) and ESR (mean 36.3 mm\h) levels. IBD were diagnosed in 9 cases (22.5%): 5 patients (12.5 %) with CD and 4 patients (10 %) - UC, in the remaining cases (77.5%) was no intestinal pathology.

Conclusion:

The results showed high frequency of IBD in patients with AS. Patients with high FC levels (more than 100 μg/g) had high disease activity (AS). In most cases, inflammatory bowel disease were diagnosed in patients with FC levels more than 100 µg/g.

References:

[1] Bernstein CN, Blanchard JF, Rawsthorne P, Yu N. The prevalence of extraintestinal diseases in inflammatory bowel disease: a population-based study. Am J Gastroenterol. 2001 Apr;96(4):1116-22.

[2] Klingberg, E., Strid, H., Stahl, A.et al. A longitudinal study of fecal calprotectin and the development of inflammatory bowel disease in ankylosing spondylitis. A longitudinal study of fecal calprotectin and the development of inflammatory bowel disease in ankylosing spondylitis. Arthritis Res Ther 2017. 19(1):21

[3] Cypers H, Varkas G, Beeckman S, et al. Elevated calprotectin levels reveal bowel inflammation in spondyloarthritis. Annals of the Rheumatic Diseases. 2016. 75:1357-1362

[4] Arzu Duran, Senol Kobak, Nazime Sen, et al. Fecal calprotectin is associated with disease activity in patients with ankylosing spondylitis. Bosnian Journal of Basic Medical Sciences. 2016. 16 (1):71-4

Disclosure of Interests:

Galina Lukina Speakers bureau: Novartis, Pfizer, UCB, Abbvie, Biocad, MSD, Roche, Polina Kulakova: None declared, Nadezhda Savenkova: None declared, Evgeniy Volnukhin: None declared, Anton Kovshik: None declared, Elena Alexandrova: None declared, Alexandr Novikov: None declared

Small Non-Coding RNA Profiling Identifies miR-181a-5p as a Mediator of Estrogen Receptor Beta-Induced Inhibition of Cholesterol Biosynthesis in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a highly heterogeneous disease, representing the most aggressive breast cancer (BC) subtype with limited treatment options due to a lack of estrogen receptor alpha (ERα), progesterone receptor (PR), and Erb-B2 receptor tyrosine kinase 2 (HER2/neu) expression. Estrogen receptor beta (ERβ) is present in a fraction of TNBC patients, where its expression correlates with improved patient outcomes, supported by the fact that it exerts oncosuppressive effects in TNBC cell models in vitro. ERβ is involved in microRNA-mediated regulation of gene expression in hormone-responsive BC cells and could mediate its actions through small noncoding RNAs (sncRNAs) in TNBCs also. To verify this possibility, smallRNA sequencing was performed on three ERβ-expressing cell lines from different TNBC molecular subtypes. Several sncRNAs resulted modulated by ERβ, with a subset being regulated in a tumor subtype-independent manner. Interestingly, sncRNA profiling of 12 ERβ+and 32 ERβ− primary TNBC biopsies identified 7 microRNAs, 1 PIWI-interacting RNA (piRNA), and 1 transfer RNA (tRNA) differentially expressed in ERβ+ compared to ERβ− tumors and cell lines. Among them, miR-181a-5p was found to be overexpressed in ERβ+ tumors and predicted target key components of the cholesterol biosynthesis pathway previously found to be inhibited by ERβ in TNBC cells.

Interaction Proteomics Identifies ERbeta Association with Chromatin Repressive Complexes to Inhibit Cholesterol Biosynthesis and Exert An Oncosuppressive Role in Triple-negative Breast Cancer

Triple-negative breast cancer (TNBC) is characterized by poor response to therapy and low overall patient survival. Recently, Estrogen Receptor beta (ERβ) has been found to be expressed in a fraction of TNBCs where, because of its oncosuppressive actions on the genome, it represents a potential therapeutic target, provided a better understanding of its actions in these tumors becomes available. To this end, the cell lines Hs 578T, MDA-MB-468 and HCC1806, representing the claudin-low, basal-like 1 and 2 TNBC molecular subtypes respectively, were engineered to express ERβ under the control of a Tetracycline-inducible promoter and used to investigate the effects of this transcription factor on gene activity. The antiproliferative effects of ERβ in these cells were confirmed by multiple functional approaches, including transcriptome profiling and global mapping of receptor binding sites in the genome, that revealed direct negative regulation by ERβ of genes, encoding for key components of cellular pathways associated to TNBC aggressiveness representing novel therapeutic targets such as angiogenesis, invasion, metastasis and cholesterol biosynthesis. Supporting these results, interaction proteomics by immunoprecipitation coupled to nano LC-MS/MS mass spectrometry revealed ERβ association with several potential nuclear protein partners, including key components of regulatory complexes known to control chromatin remodeling, transcriptional and post-transcriptional gene regulation and RNA splicing. Among these, ERβ association with the Polycomb Repressor Complexes 1 and 2 (PRC1/2), known for their central role in gene regulation in cancer cells, was confirmed in all three TNBC subtypes investigated, suggesting its occurrence independently from the cellular context. These results demonstrate a significant impact of ERβ in TNBC genome activity mediated by its cooperation with regulatory multiprotein chromatin remodeling complexes, providing novel ground to devise new strategies for the treatment of these diseases based on ligands affecting the activity of this nuclear receptor or some of its protein partners.

Inhibition of histone methyltransferase DOT1L silences ERα gene and blocks proliferation of antiestrogen-resistant breast cancer cells

Breast cancer (BC) resistance to endocrine therapy results from constitutively active or aberrant estrogen receptor α (ERα) signaling, and ways to block ERα pathway in these tumors are sought after. We identified the H3K79 methyltransferase DOT1L as a novel cofactor of ERα in BC cell chromatin, where the two proteins colocalize to regulate estrogen target gene transcription. DOT1L blockade reduces proliferation of hormone-responsive BC cells in vivo and in vitro, consequent to cell cycle arrest and apoptotic cell death, with widespread effects on ER-dependent gene transcription, including ERα and FOXA1 gene silencing. Antiestrogen-resistant BC cells respond to DOT1L inhibition also in mouse xenografts, with reduction in ERα levels, H3K79 methylation, and tumor growth. These results indicate that DOT1L is an exploitable epigenetic target for treatment of endocrine therapy-resistant ERα-positive BCs.

Quantitative mapping of RNA-mediated nuclear estrogen receptor β interactome in human breast cancer cells

The nuclear receptor estrogen receptor 2 (ESR2, ERβ) modulates cancer cell proliferation and tumor growth, exerting an oncosuppressive role in breast cancer (BC). Interaction proteomics by tandem affinity purification coupled to mass spectrometry was previously applied in BC cells to identify proteins acting in concert with ERβ to control key cellular functions, including gene transcription, RNA splicing and post-transcriptional mRNA regulation. These studies revealed an involvement of RNA in ERβ interactome assembly and functions. By applying native protein complex purification followed by nano LC-MS/MS before and after in vitro RNA removal, we generated a large dataset of newly identified nuclear ERβ interactors, including a subset associating with the receptor via RNA bridging. These datasets will be useful to investigate further the role of ERβ, nuclear RNAs and the other proteins identified here in BC and other cell types.

Large-scale profiling of signalling pathways reveals an asthma specific signature in bronchial smooth muscle cells

Background

Bronchial smooth muscle (BSM) cells from asthmatic patients maintain in vitro a distinct hyper-reactive (“primed”) phenotype, characterized by increased release of pro-inflammatory factors and mediators, as well as hyperplasia and/or hypertrophy. This “primed” phenotype helps to understand pathogenesis of asthma, as changes in BSM function are essential for manifestation of allergic and inflammatory responses and airway wall remodelling.

Objective

To identify signalling pathways in cultured primary BSMs of asthma patients and non-asthmatic subjects by genome wide profiling of differentially expressed mRNAs and activated intracellular signalling pathways (ISPs).

Methods

Transcriptome profiling by cap-analysis-of-gene-expression (CAGE), which permits selection of preferentially capped mRNAs most likely to be translated into proteins, was performed in human BSM cells from asthmatic (n=8) and non-asthmatic (n=6) subjects and OncoFinder tool were then exploited for identification of ISP deregulations.

Results

CAGE revealed >600 RNAs differentially expressed in asthma vs control cells (p≤0.005), with asthma samples showing a high degree of similarity among them. Comprehensive ISP activation analysis revealed that among 269 pathways analysed, 145 (p<0.05) or 103 (p<0.01) are differentially active in asthma, with profiles that clearly characterize BSM cells of asthmatic individuals. Notably, we identified 7 clusters of coherently acting pathways functionally related to the disease, with ISPs down-regulated in asthma mostly targeting cell death-promoting pathways and up-regulated ones affecting cell growth and proliferation, inflammatory response, control of smooth muscle contraction and hypoxia-related signalization.

Conclusions

These first-time results can now be exploited toward development of novel therapeutic strategies targeting ISP signatures linked to asthma pathophysiology.

Small non-coding RNA deregulation in endometrial carcinogenesis

Small non-coding RNAs (sncRNAs) represent a heterogeneous group of <200nt-long transcripts comprising microRNAs, PIWI-interacting RNAs (piRNAs) and small-nucleolar-RNAs (snoRNAs) involved in physiological and pathological processes such as carcinogenesis and tumor progression. Aberrant sncRNA expression in cancer has been associated with specific clinical phenotypes, grading, staging, metastases development and resistance to therapy.Aim of the present work is to study the role of sncRNAs in endometrial carcinogenesis. Changes in sncRNA expression were identified by high-throughput genomic analysis of paired normal, hyperplastic and cancerous endometrial tissues obtained by endometrial biopsies (n = 10). Using smallRNA sequencing and microarrays we identified significant differences in sncRNA expression pattern between normal, hyperplastic and neoplastic endometrium. This led to the definition of a sncRNA signature (129 microRNAs, 2 of which not previously described, 10 piRNAs and 3 snoRNAs) of neoplastic transformation. Functional bioinformatics analysis identified as downstream targets multiple signaling pathways potentially involved in the hyperplastic and neoplastic tissue responses, including Wnt/β-catenin, and ERK/MAPK and TGF-β-Signaling.Considering the regulatory role of sncRNAs, this newly identified sncRNA signature is likely to reflect the events leading to endometrial cancer, which can be exploited to dissect the carcinogenic process including novel biomarkers for early and non-invasive diagnosis of these tumors.

Small RNA profiling reveals deregulated phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/Akt pathway in bronchial smooth muscle cells from asthmatic patients

BACKGROUND

Aberrant expression of small noncoding RNAs (sncRNAs), microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs) in particular, define several pathologic processes. Asthma is characterized by airway hyperreactivity, chronic inflammation, and airway wall remodeling. Asthma-specific miRNA profiles were reported for bronchial epithelial cells, whereas sncRNA expression in asthmatic bronchial smooth muscle (BSM) cells is almost completely unexplored.

OBJECTIVE

We sought to determine whether the primary BSM sncRNA expression profile is altered in asthmatic patients and identify targets of differentially expressed sncRNAs.

METHODS

Small RNA sequencing was used for sncRNA profiling in BSM cells (from 8 asthmatic and 6 nonasthmatic subjects). sncRNA identification and differential expression analysis was performed with iMir software. Experimentally validated miRNA targets were identified by using Ingenuity Pathway Analysis, and putative piRNA targets were identified by using miRanda software.

RESULTS

BSM cells from asthmatic patients showed abnormal expression of 32 sncRNAs (26 miRNAs, 5 piRNAs, and 1 small nucleolar RNA). Target prediction for deregulated miRNAs and piRNAs revealed experimentally validated and predicted mRNA targets expressed in the BSM cells. Thirty-eight of these mRNAs represent major targets for deregulated miRNAs and might play important roles in the pathophysiology of asthma. Interestingly, 6 of these mRNAs were previously associated with asthma, considered as novel therapeutic targets for treatment of this disease, or both. Signaling pathway analysis revealed involvement of 38 miRNA-targeted mRNAs in increased cell proliferation through phosphatase and tensin homolog and phosphoinositide 3-kinase/Akt signaling pathways.

CONCLUSIONS

BSM cells of asthmatic patients are characterized by aberrant sncRNA expression that recapitulates multiple pathologic phenotypes of these cells.

Ipsilateral in-breast tumor recurrence after breast conserving therapy: true recurrence versus new primary tumor

PURPOSE

To classify ipsilateral in-breast cancer recurrences (IBCR) in patients treated with conservative surgery and radiation therapy, either as new primary tumor (NP) or true recurrence (TR) and to assess the prognostic and therapeutic importance of this classification.

METHODS

The records of 107 patients treated for local tu- mor recurrence after breast-conserving therapy (BCT) at the National Cancer Center, Sofia, between March 1999 and May 2011 were retrospectively analysed. The patients'primary tumors were up to 2 cm in size. For their primary tumors all patients underwent quadrantectomy, axillary lymph node dissection and postoperative radiotherapy (RT) up to 50 Gy. In cases with nodal metastasis additional RT has been used. Adjuvant chemotherapy and hormonotherapy have been used according to the clinical indications and depending of the patient's condition. Every attempt was made to define a tumor as a TR or NP, based on the changes in location and histology. (99m)Tc-MIBI SPECT-CT was used to localize the site of recurrence.

RESULTS

Forty-four (41.1%) of the relapses were TR and 63 (58.9%) NPs. Out of 63 relapses defined as NPs, 54 (85.7%) changed the location and 49 (68.3%) had a different histology. The age of patients with TR and with NP did not differ significantly at the time of diagnosis of the primary tumor (TR 48.8±10.45 years vs NP 50.8±10.56; p<0.330), but those who developed TR were significantly younger than those with NP at the time of recurrence (TR 53 years, 66±11.1 vs NP 58.15+10.6; p<0.05). Recurrences defined as NPs, developed after a significantly longer period of time in comparison to the TRs (7.4±2.6 years vs 4.8±2.2 years; p<0.0001). Five-year overall survival of patients with TR was significantly lower compared to patients with NP (31.8% vs 96.7% p=0.0001).

CONCLUSIONS

Recurrences developing after BCT represent different clinical events, having different origin, prognosis and, therefore, requiring different type of treatment. It seems that a significant part of the recurrences that develop in the residual parenchyma, following BCT, are new carcinomas.

SPECT-CT in Radiotherapy Planning, with Main Reference to Patients with Breast Cancer

The aim of modern intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) is to define the target areas including the smallest non-invaded margins, thus reducing the radiation dose to radiosensitive organs. To reach this goal, these methods require a more precise target delineation by imaging to better define the viable part of the tumor. Image-guided selection and demarcation of Gross Tumor Volume (GTV), Clinical Target Volume (CTV) and Organs at Risk (OAR) are the main steps to reach a satisfactory radiation treatment plan. Hybrid machines, such as PET-CT, SPECT-CT and, more recently, PET-MRI, may significantly increase diagnostic accuracy improving either sensitivity and specificity achievable alone by the single constituents of the hybrid tools. While the implementation contribution of PET-CT in radiotherapy, with respect to CT stand alone, has been extensively and successfully investigated, few papers have been at present written on the possible role of SPECT-CT for the same purpose. With an identical contribution to CT, SPECT may give similar information with respect to PET, when suitable radiopharmaceuticals are available. In particular, SPECT may provide additional information to CT, better defining the viable tumor mass; as a consequence, a more effective delineation of the GTV, saving the maximum normal tissue as possible, may be allowed. In this paper, we review some of the most important applications of SPECT-CT in oncology, as a premise to its possible utilization in tumor target definition in radiotherapy. In particular, we discuss sentinel lymph node (SLN) detection, tumor imaging with cationic lipophilic radiotracers, as (99m)Tc-methoxyisobutylisonitrile (MIBI) and (99m)Tc-tetrofosmin (TF) in breast cancer, thymoma, and lung cancer, (99m)Tcmethylene diphosphonate (MDP) for bone scan, (131)Iodine and (123)Iodine in differentiated thyroid cancer (DTC), as useful methods to optimize GTV and CTV definition. A reflection on the possible role in radiotherapy of other radiotracers labeled with gamma emitters, such as In-111 pentreotide has also been included.

Identification of cytoplasmic proteins interacting with unliganded estrogen receptor α and β in human breast cancer cells

Estrogen receptor subtypes (ERα and ERβ) are transcription factors sharing a similar structure but exerting opposite roles in breast cancer cells. Besides the well-characterized genomic actions of nuclear ERs upon ligand binding, specific actions of ligand-free ERs in the cytoplasm also affect cellular functions. The identification of cytoplasmic interaction partners of unliganded ERα and ERβ may help characterize the molecular basis of the extra-nuclear mechanism of action of these receptors, revealing novel mechanisms to explain their role in breast cancer response or resistance to endocrine therapy. To this aim, cytoplasmic extracts from human breast cancer MCF-7 cells stably expressing tandem affinity purification-tagged ERα and ERβ and maintained in estrogen-free medium were subject to affinity-purification and MS analysis, leading to the identification of 84 and 142 proteins associated with unliganded ERα and ERβ, respectively. Functional analyses of ER subtype-specific interactomes revealed significant differences in the molecular pathways targeted by each receptor in the cytoplasm. This work, reporting the first identification of the unliganded ERα and ERβ cytoplasmic interactomes in breast cancer cells, provides novel experimental evidence on the nongenomic effects of ERs in the absence of hormonal stimulus. All MS data have been deposited in the ProteomeXchange with identifier PXD001202 (http://proteomecentral.proteomexchange.org/dataset/PXD001202).

[Breast cancer developing during pregnancy--clinical cases and review of the literature]

The goal of the present paper is to discuss diagnosis, treatment approaches and histopathologic characteristics of breast cancer developing during pregnancy, based on our results and published literature data. We retrospectively evaluated clinical and pathologic features of tumors, treatment methods, decisions related to pregnancy and final outcome by eight pregnant patients with breast cancer. The patients' age varied from 26 to 36 years. At the last medical examination in October 2013, three among all eight patients were alive, two of them were without local and distant recurrence, and one patient has distant metastases and is carrying out a treatment. The aim of this paper was to discuss the characteristics of breast cancer developing during pregnancy. Retrospectively have been analyzed clinical-pathological characteristics of the tumors in eight pregnant women with breast cancer, the treatment, the management of the pregnancy, and the final outcome. The results are analyzed by comparing with data published in the literature.

Primary angiosarcoma of the breast complicated by the syndrome of disseminated intravascular coagulation (DIC): Case report and literature review

Primary angiosarcoma of the breast (PAB) accounts for 0.04% of all breast malignant tumors. It affects young women usually at third or fourth decades of life. PAB clinically manifests as a painless, movable mass with sharp limits. A bluish red discoloration of the overlying skin is often observed. Enlargement of axillary lymph nodes generally does not occur. Angiosarcoma of the breast has a very poor prognosis due to the tendency to metastasize haematogenously and high frequency of local recurrence. Mastectomy and chemotherapy are preferable treatment choices. This paper presents a case of primary angiosarcoma of the breast with a syndrome of disseminated intravascular coagulation (DIC).