The Role of lncRNAs in Rare Tumors with a Focus on HOX Transcript Antisense RNA (HOTAIR).

Rare cancers are identified as those with an annual incidence of fewer than 6 per 100,000 persons and includes both epithelial and stromal tumors from different anatomical areas. The advancement of analytical methods has produced an accurate molecular characterization of most human cancers, suggesting a "molecular classification" that has allowed the establishment of increasingly personalized therapeutic strategies. However, the limited availability of rare cancer samples has resulted in very few therapeutic options for these tumors, often leading to poor prognosis. Long non coding RNAs (lncRNAs) are a class of non-coding RNAs mostly involved in tumor progression and drug response. In particular, the lncRNA HOX transcript antisense RNA (HOTAIR) represents an emergent diagnostic, prognostic and predictive biomarker in many human cancers. The aim of this review is to highlight the role of HOTAIR in rare cancers, proposing it as a new biomarker usable in the management of these tumors.

Aberrant Expression of Long Non Coding RNA HOTAIR and De-Regulation of the Paralogous 13 HOX Genes Are Strongly Associated with Aggressive Behavior of Gastro-Entero-Pancreatic Neuroendocrine Tumors.

Gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs) are rare diseases occurring in the gastrointestinal tract and pancreas. They are characterized by the loss of epithelial tubular gland elements, and by the increased expression of neuroendocrine markers. GEP-NENs are subdivided into two histo-pathological types, gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) and gastro-entero-pancreatic neuroendocrine carcinomas (GEP-NECs). According to WHO 2017 and 2019 classification criteria are graded and staged in four categories, NET-G1, NET-G2, NET-G3, and NEC-G3. The molecular characterization of these tumors can be fundamental for the identification of new diagnostic, prognostic and predictive biomarkers. The main purpose of this study was to analyze the expression of the paralogous 13 HOX genes, normally involved in embryogenic development and frequently deregulated in human cancers, and of the HOX regulating lncRNA HOTAIR in GEP-NENs. The expression of HOX genes is gradually lost in the transition from GEP NET G1 to NET/NEC G3 tumors, while HOTAIR expression, inversely correlated with HOX genes expression and weakly expressed in low-grade GEP NENs, becomes aberrant in NET G3 and NEC G3 categories. Our data highlights their potential role in the molecular stratification of GEP-NENs by suggesting new prognostic markers and potential therapeutic targets.

Noncoding RNAs within the HOX gene network in tumor pathogenesis and progression.

HOX genes are involved with normal development, cell identity, cell differentiation, cell metabolism, apoptosis, autophagy as well as with diseases such as tumor pathogenesis and progression. In particular, the genes belonging to HOX paralogous 13 seem to carry out a relevant role in both tumor development and disease progression. In recent years, several noncoding RNAs (ncRNA) sequences have been identified in HOX loci, including long noncoding RNA (lncRNA) and microRNA (miRNA), highly conserved during evolution. Many studies have shown that specific intergenic ncRNAs in HOX loci could directly modulate HOX genes expression in normal and pathological conditions. In the present review we attempt to describe the role of these ncRNAs, through the regulation of the HOX gene network, in normal cell biology, and, with particular emphasis, in diseases such as in cancer pathogenesis and progression.

Sex Hormone Receptors in Benign and Malignant Salivary Gland Tumors: Prognostic and Predictive Role.

The role of sex hormone receptors in human cancer development and progression has been well documented in numerous studies, as has the success of sex hormone antagonists in the biological therapy of many human tumors. In salivary gland tumors (SGTs), little and conflicting information about the role of the estrogen receptor alpha (ERα), progesterone receptor (PgR) and androgen receptor (AR) has been described and in most cases the use of sex hormone antagonists is not contemplated in clinical practice. In this study, we analyzed a panel of sex hormone receptors that have not been widely investigated in SGTs-ERα, PgR, AR, but also ERß and GPR30-to define their expression pattern and their prognostic and predictive value in a case series of 69 benign and malignant SGTs. We showed the aberrant expression of AR in mucoepidermoid and oncocytic carcinoma, a strong relation between cytoplasmic ERß expression and tumor grade, and a strong correlation between nuclear GPR30 expression and disease-free survival (DFS) of SGT patients.

COX-2 expression positively correlates with PD-L1 expression in human melanoma cells.

BACKGROUND: The resistance to PD-1/PD-L1 inhibitors for the treatment of melanoma have prompted investigators to implement novel clinical trials which combine immunotherapy with different treatment modalities. Moreover is also important to investigate the mechanisms which regulate the dynamic expression of PD-L1 on tumor cells and PD-1 on T cells in order to identify predictive biomarkers of response. COX-2 is currently investigated as a major player of tumor progression in several type of malignancies including melanoma. In the present study we investigated the potential relationship between COX-2 and PD-L1 expression in melanoma. METHODS: Tumor samples obtained from primary melanoma lesions and not matched lymph node metastases were analyzed for both PD-L1 and COX-2 expression by IHC analysis. Status of BRAF and NRAS mutations was analyzed by sequencing and PCR. Co-localization of PD-L1 and COX-2 expression was analyzed by double fluorescence staining. Lastly the BRAFV600E A375 and NRASQ61R SK-MEL-2 melanoma cell lines were used to evaluate the effect of COX-2 inhibition by celecoxib on expression of PD-L1 in vitro. RESULTS: BRAFV600E/V600K and NRASQ61R/Q61L were detected in 57.8 and 8.9% of the metastatic lesions, and in 65.9 and 6.8% of the primary tumors, respectively. PD-L1 and COX-2 expression were heterogeneously expressed in both primary melanoma lesions and not matched lymph node metastases. A significantly lower number of PD-L1 negative lesions was found in primary tumors as compared to not matched metastatic lesions (P = 0.002). COX-2 expression significantly correlated with PD-L1 expression in both primary (P = 0.001) and not matched metastatic (P = 0.048) lesions. Furthermore, in melanoma tumors, cancer cells expressing a higher levels of COX-2 also co-expressed a higher level of PD-L1. Lastly, inhibition of COX-2 activity by celecoxib down-regulated the expression of PD-L1 in both BRAFV600E A375 and NRASQ61R SK-MEL-2 melanoma cell lines. CONCLUSIONS: COX-2 expression correlates with and modulates PD-L1 expression in melanoma cells. These findings have clinical relevance since they provide a rationale to implement novel clinical trials to test COX-2 inhibition as a potential treatment to prevent melanoma progression and immune evasion as well as to enhance the anti-tumor activity of PD-1/PD-L1 based immunotherapy for the treatment of melanoma patients with or without BRAF/NRAS mutations.

Endocrine nuclear receptors and long non­coding RNAs reciprocal regulation in cancer (Review).

Nuclear receptors (NRs) are transcriptional regulators involved in different aspects of normal cell physiology. Their deregulation is associated with aberrant expression, gene mutations and/or epigenetic alterations that can be related to the pathogenesis of various human diseases, and especially in cancer. In particular, a complex genomic network involved in the development and progression of NR­mediated cancer has been highlighted. Advanced genomic technologies have made it possible to understand that the expression of any particular NR in a given cancer subtype is only one component of a larger transcriptional machinery that is controlled by multiple associated NRs and transcription factors. Additionally, their ability to regulate and to be regulated by molecules of non­coding RNAs, microRNAs as well as long non­coding RNAs, is opening new scenarios for understanding the role of NRs in cancer initiation and progression. In the present review, the authors aimed to outline the reciprocal interactions that exist between the main NRs and long non­coding RNAs in different tumor diseases, to suggest new diagnostic biomarkers as well as therapeutic strategies for these tumors.

Bispecific aptamer-decorated and light-triggered nanoparticles targeting tumor and stromal cells in breast cancer derived organoids: implications for precision phototherapies.

BACKGROUND: Based on the established role of cancer-stroma cross-talk in tumor growth, progression and chemoresistance, targeting interactions between tumor cells and their stroma provides new therapeutic approaches. Dual-targeted nanotherapeutics selectively acting on both tumor and stromal cells may overcome the limits of tumor cell-targeting single-ligand nanomedicine due to the complexity of the tumor microenvironment. METHODS: Gold-core/silica-shell nanoparticles embedding a water-soluble iridium(III) complex as photosensitizer and luminescent probe (Iren-AuSiO2_COOH) were efficiently decorated with amino-terminated EGFR (CL4) and PDGFRß (Gint4.T) aptamers (Iren-AuSiO2_Aptamer). The targeting specificity, and the synergistic photodynamic and photothermal effects of either single- and dual-aptamer-decorated nanoparticles have been assessed by confocal microscopy and cell viability assays, respectively, on different human cell types including mesenchymal subtype triple-negative breast cancer (MES-TNBC) MDA-MB-231 and BT-549 cell lines (both EGFR and PDGFRß positive), luminal/HER2-positive breast cancer BT-474 and epidermoid carcinoma A431 cells (only EGFR positive) and adipose-derived mesenchymal stromal/stem cells (MSCs) (only PDGFRß positive). Cells lacking expression of both receptors were used as negative controls. To take into account the tumor-stroma interplay, fluorescence imaging and cytotoxicity were evaluated in preclinical three-dimensional (3D) stroma-rich breast cancer models. RESULTS: We show efficient capability of Iren-AuSiO2_Aptamer nanoplatforms to selectively enter into target cells, and kill them, through EGFR and/or PDGFRß recognition. Importantly, by targeting EGFR+ tumor/PDGFRß+ stromal cells in the entire tumor bulk, the dual-aptamer-engineered nanoparticles resulted more effective than unconjugated or single-aptamer-conjugated nanoparticles in either 3D spheroids cocultures of tumor cells and MSCs, and in breast cancer organoids derived from pathologically and molecularly well-characterized tumors. CONCLUSIONS: Our study proposes smart, novel and safe multifunctional nanoplatforms simultaneously addressing cancer-stroma within the tumor microenvironment, which are: (i) actively delivered to the targeted cells through highly specific aptamers; (ii) localized by means of their luminescence, and (iii) activated via minimally invasive light, launching efficient tumor death, thus providing innovative precision therapeutics. Given the unique features, the proposed dual targeted nanoformulations may open a new door to precision cancer treatment.

TLR4 Expression in Ex-Lichenoid Lesions-Oral Squamous Cell Carcinomas and Its Surrounding Epithelium: The Role of Tumor Inflammatory Microenvironment.

Toll-like receptors (TLRs) regulate innate and adaptive immune responses. Moreover, TLRs can induce a pro-survival and pro-proliferation response in tumor cells. This study aims to investigate the expression of TLR4 in the epithelium surrounding oral squamous cell carcinomas (OSCC) in relation to its inflammatory microenvironment. This study included 150 human samples: 30 normal oral control (NOC), 38 non-lichenoid epithelium surrounding OSCC (NLE-OSCC), 28 lichenoid epithelium surrounding OSCC (LE-OSCC), 30 OSCC ex-non oral lichenoid lesion (OSCC Ex-NOLL), and 24 OSCC ex-oral lichenoid lesion (OSCC Ex-OLL). TLR4 expression was investigated by immunohistochemistry and the percentage of positive cells was quantified. In addition, a semiquantitative analysis of staining intensity was performed. Immunohistochemical analysis revealed that TLR4 is strongly upregulated in LE-OSCC as compared to normal control epithelium and NLE-OSCC. TLR4 expression was associated with the inflammatory environment, since the percentage of positive cells increases from NOC and NLE-OSCC to LE-OSCC, reaching the highest value in OSCC Ex-OLL. TLR4 was detected in the basal third of the epithelium in NLE-OSCC, while in LE-OSCC, TLR4 expression reached the intermediate layer. These results demonstrated that an inflammatory microenvironment can upregulate TLR4, which may boost tumor development.

The Ratio of GrzB+ - FoxP3+ over CD3+ T Cells as a Potential Predictor of Response to Nivolumab in Patients with Metastatic Melanoma.

The understanding of the molecular pathways involved in the dynamic modulation of the tumor microenvironment (TME) has led to the development of innovative treatments for advanced melanoma, including immune checkpoint blockade therapies. These approaches have revolutionized the treatment of melanoma, but are not effective in all patients, resulting in responder and non-responder populations. Physical interactions among immune cells, tumor cells and all the other components of the TME (i.e., cancer-associated fibroblasts, keratinocytes, adipocytes, extracellular matrix, etc.) are essential for effective antitumor immunotherapy, suggesting the need to define an immune score model which can help to predict an efficient immunotherapeutic response. In this study, we performed a multiplex immunostaining of CD3, FOXP3 and GRZB on both primary and unmatched in-transit metastatic melanoma lesions and defined a novel ratio between different lymphocyte subpopulations, demonstrating its potential prognostic role for cancer immunotherapy. The application of the suggested ratio can be useful for the stratification of melanoma patients that may or may not benefit from anti-PD-1 treatment.

Regulatory T cell frequency in patients with melanoma with different disease stage and course, and modulating effects of high-dose interferon-alpha 2b treatment.

BACKGROUND: High-dose interferon-alpha 2b (IFN-alpha 2b) is the only approved systemic therapy in the United States for the adjuvant treatment of melanoma. The study objective was to explore the immunomodulatory mechanism of action for IFN-alpha 2b by measuring serum regulatory T cell (Treg), serum transforming growth factor-beta (TGF-beta), interleukin (IL)-10, and autoantibody levels in patients with melanoma treated with the induction phase of the high-dose IFN-alpha 2b regimen. METHODS: Patients with melanoma received IFN-alpha 2b administered intravenously (20 MU/m2 each day from day 1 to day 5 for 4 consecutive weeks). Serum Treg levels were measured as whole lymphocytes in CD4+ cells using flow cytometry while TGF-beta, IL-10, and autoantibody levels were measured using enzyme-linked immunosorbent assays. RESULTS: Twenty-two patients with melanoma received IFN-alpha 2b treatment and were evaluated for Treg levels. Before treatment, Treg levels were significantly higher in patients with melanoma when compared with data from 20 healthy subjects (P = 0.001; Mann-Whitney test). Although a trend for reduction of Treg levels following IFN-α 2b treatment was observed (average decrease 0.29% per week), statistical significance was not achieved. Subgroup analyses indicated higher baseline Treg levels for stage III versus IV disease (P = 0.082), early recurrence versus no recurrence (P = 0.017), deceased versus surviving patients (P = 0.021), and preoperative neoadjuvant versus postoperative adjuvant treatment groups (not significant). No significant effects were observed on the levels of TGF-beta, IL-10, and autoantibodies in patients with melanoma treated with IFN-alpha 2b. CONCLUSIONS: Patients with melanoma in this study showed increased basal levels of Treg that may be relevant to their disease and its progression. Treg levels shifted in patients with melanoma treated with IFN-alpha 2b, although no firm conclusions regarding the role of Tregs as a marker of treatment response or outcome can be made at present.

Long Non-Coding RNA HOTAIR in Breast Cancer Therapy.

Breast cancer (BC) is the most common cancer type among women, and morbidity and mortality rates are still very high. Despite new innovative therapeutic approaches for all BC molecular subtypes, the discovery of new molecular biomarkers involved in tumor progression has been fundamental for the implementation of personalized treatment strategies and improvement of patient management. Many experimental studies indicate that long non-coding RNAs (lncRNAs) are strongly involved in BC initiation, metastatic progression, and drug resistance. In particular, aberrant expression of HOX transcript antisense intergenic RNA (HOTAIR) lncRNA plays an important role in BC contributing to its progression and represents a predictor of BC metastasis. For its proven prognostic value, HOTAIR could represent a potential therapeutic target in BC. In the present review, we summarize the role of HOTAIR in cancer progression and drug resistance, in particular in BC, and we illustrate the main approaches for silencing it.

Immunohistochemical detection of paralogous 13 HOX genes in phyllodes tumor of the breast as a useful diagnostic tool.

Phyllodes tumor of the breast is a rare fibroepithelial lesion characterized by a propensity for local recurrence and distant metastasis. Its histologic classification, based on morphology, mitotic index and tumor margin, includes malignant, borderline, and benign. These tumors show similar cellular morphology, which may contribute to difficulty in classifying them histologically and in prediction of their clinical behavior. Thus, the identification of new biomarkers detectable also by in situ methods has become indispensable. Paralogous HOX13 genes (HOX A13, HOX B13, HOX C13 and HOX D13) play a relevant role in tumor development and progression in particular in breast cancer. In this study we analyzed the immunohistochemical expression of paralogous HOX13 homeoproteins on a phyllodes tumor case series to validate their usefulness in histologic classification.

Morphological and pathological features of basal-like breast cancer.

Basal-like breast cancer (BLBC) is characterized by high grade, high mitotic indices, presence of central necrotic or fibrotic zones, and lymphocytic infiltrate. Patients presenting with BLBC have a poor prognosis and a short-term disease-free and overall survival. BLBCs may include different histological types of breast cancers but the most common histological type is represented by invasive ductal carcinomas of no special type (IDC-NST). Typical immunohistochemical markers for these tumors are basal-type cytokeratin markers such as CK5/6, CK14, CK17, but several BLBCs also express luminal-type CKs, such as CK8/18, CK19. Different molecular alterations, including BRCA1 dysfunction, p53 mutations, up-regulation of EGFR, inactivation of PTEN and the aberrant expression of many non-coding RNAs molecules are detected in BLBC cells suggesting the possibility of defining new targeted therapeutic strategies for this tumor type.

Geo-location of Oncological Diseases in the Extra-urban Areas of Naples and Creation of Territorial Biobanks: An Important Tool to Study Potential Connections Between Environmental Factors and Cancer.

Many areas of the Campania region of Italy are more frequently at risk of neoplastic diseases due to environmental factors. However, the results of epidemiological studies, although numerous and detailed, do not explain tumor pathogenesis mechanisms in relation to the contribution of exposure to environmental pollutants. The Oncological Biobank of the G. Pascale Foundation (BBI) centralizes the collection and storage of biomaterials, both healthy and pathological human tissues, from urban and extra-urban areas of Naples, associating them with clinicopathological characteristics (type of tumor, histological type, grading, immunohistochemical and molecular profile, etc.). Geo-location of tumor samples is made by an IT platform in which demographic and clinical data are systematically uploaded. For the extra-urban areas of Naples, our experience of tumor sample geolocation highlighted cancer types with high impact of environmental pollutants as being lung, gastric and bladder cancer. In this mini-review, we underline that the possibility of specifically selecting tumor samples in circumscribed territories may allow targeted studies to verify potential connections between environmental factors and cancer. Moreover, the collection of biological fluids (serum, saliva, urine) from healthy individuals from specific areas may be a useful tool for the research of specific genetic polymorphisms linked to individual susceptibility.

Large polypoid perineurioma of the transverse colon without crypt serration (NPS).

Intestinal perineuriomas without crypt serration are mainly polypoid lesions characterized by a proliferation of stromal cells expressing perineurial markers. These lesions morphologically differ from those with serrated crypts because of the serrated/hyperplastic architecture in addition to the disorganization of the crypts. These tumors, despite both expression of perineurial cell markers (epithelial membrane antigen, claudin-1, GLUT-1, and collagen type IV), show well-characterized molecular differences such as BRAFV600E mutation, suggesting that they might represent two distinct variants of a single lesion. In this report, we describe a polypoid intestinal perineurioma without crypt serration of the transverse colon, showing an unusual large size compared with other reported polypoid lesions ranging from 0.2 to 0.6 cm in size.

LncRNA HOTAIR Polymorphisms Association with Cancer Susceptibility in Different Tumor Types.

Single nucleotide polymorphisms (SNPs) in non-coding RNAs (ncRNA) molecules affect gene and protein expression and generate genetic variability influencing the risk of tumor diseases. HOTAIR locates at the heart of the cell memory gene program and represents a prototype of long non coding RNA (LncRNA) due to its capacity to regulate in-trans a distant chromosome landscape. Aberrant expression of HOTAIR is frequently associated with pathogenesis and mostly with metastatic progression of several human cancers. Different polymorphisms, particularly present in intronic sequences, as well as in promoter regions of HOTAIR, are often associated with its aberrant expression, patient prognosis, and cancer susceptibility in different tumor phenotypes. In this minireview, we have summarized the main SNPs in HOTAIR sequence and their relation with cancer risk in several types of solid tumors.

Downregulation of androgen receptor is strongly associated with diabetes in triple negative breast cancer patients.

Developing of personalized therapies for Triple Negative Breast Cancer (TNBC) requires a more detailed knowledge of its biology and a correct stratification of molecular subtypes. Androgen Receptor (AR) is expressed in a large part of TNBCs but its prognostic role in this Breast Cancer (BC) subtype is highly debated. In this study, we analyzed AR expression in a series of 238 TNBCs and correlated its expression with clinical-pathological features, survival, and metabolic profile. We showed a consistent association between AR expression and a better prognosis of TNBC patients, while its downregulation appeared strongly associated with diabetic disease. Since a recent prospective study reported a lower BC risk in diabetic women treated with drugs able to reduce circulating levels of glucose compared with non-diabetic woman, and in vitro studies showed that AR level are regulated directly by hyperglycemia, we speculate on the perspective of new integrated therapies for TNBC.

Prognostic Value of Cancer Stem Cells Markers in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) has a significant clinical relevance of being associated with a shorter median time to relapse and death and does not respond to endocrine therapy or other available targeted agents. Increased aggressiveness of this tumor, as well as resistance to standard drug therapies, may be associated with the presence of stem cell populations within the tumor. Several stemness markers have been described for the various histological subtypes of breast cancer, such as CD44, CD24, CD133, ALDH1, and ABCG2. The role of these markers in breast cancer is not clear yet and above all there are conflicting opinions about their real prognostic value. To investigate the role of CSCs markers in TNBC cancerogenesis and tumor progression, we selected 160 TNBCs samples on which we detected protein expression of CD44, CD24, CD133, ALDH1, and ABCG2 by immunohistochemistry. Our results highlighted a real prognostic role only for CD44 in TNBCs. All other CSCs markers do not appear to be related to the survival of TNBC patients. In conclusion, despite the fact that the presence of the cancer stem cells in the tumor provides important information on its potential aggressiveness, today their detection by immunohistochemistry is not sufficient to confirm their role in carcinogenesis, because specific markers probably are not yet identified.