Association of PD-1 and PD-L1 protein expression with selected clinical and morphological parameters in colorectal cancers.

Colorectal cancer is the third most common cancer worldwide and the second cause of death from malignant tumors. Colorectal cancers are treated with surgery, chemotherapy, gene therapy and immunotherapy. PD-1 and PD-L1 proteins have recently been considered as potential targets of anticancer therapy in colorectal cancer. The aim of this study was to evaluate the association of immunohistochemical expression of PD-1 and PD-L1 proteins in colorectal cancer patients with selected clinical and morphological parameters and their survival. Ninety-eight cases of colorectal cancer were studied. Immunohistochemistry was used to evaluate the expression of PD-1 and PD-L1 proteins. Correlations were found between the expression of PD-L1 protein in lymphocytes and lack of lymph node metastases and a lower clinical stage. There was also a correlation between PD-L1 protein expression in cancer cells and a higher grade of histological malignancy.

Diagnostic Potential of miR-143-5p, miR-143-3p, miR-551b-5p, and miR-574-3p in Chemoresistance of Locally Advanced Gastric Cancer: A Preliminary Study.

Gastric cancer (GC) is one of the most frequently diagnosed cancers in the world. Although the incidence is decreasing in developed countries, the treatment results are still unsatisfactory. The standard treatment for locally advanced gastric cancer (LAGC) is gastrectomy with perioperative chemotherapy. The association of selected microRNAs (miRNAs) with chemoresistance was assessed using archival material of patients with LAGC. Histological material was obtained from each patient via a biopsy performed during gastroscopy and then after surgery, which was preceded by four cycles of neoadjuvant chemotherapy (NAC) according to the FLOT or FLO regimen. The expression of selected miRNAs in the tissue material was assessed, including miRNA-21-3p, miRNA-21-5p, miRNA-106a-5p, miRNA-122-3p, miRNA-122-5p, miRNA-143-3p, miRNA-143-5p, miRNA-203a-3p, miRNA-203-5p, miRNA-551b-3p, miRNA-551b-5p, and miRNA-574-3p. miRNA expression was assessed using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The response to NAC was assessed using computed tomography of the abdomen and chest and histopathology after gastrectomy. The statistical analyses were performed using GraphPad Prism 9. The significance limit was set at p < 0.05. We showed that the expression of miR-143-3p, miR-143-5p, and miR-574-3p before surgery, and miR-143-5p and miR-574-3p after surgery, decreased in patients with GC. The expression of miR-143-3p, miR-143-5p, miR-203a-3p, and miR-551b-5p decreased in several patients who responded to NAC. The miRNA most commonly expressed in these cases was miRNA-551b-5p. Moreover, it showed expression in a patient whose response to chemotherapy was inconsistent between the histopathological results and computed tomography. The expression of miR-143-3p, miR-143-5p, miR-203a-3p, and miR-551b-5p in formalin-fixed paraffin-embedded tissue (FFPET) samples can help differentiate between the responders and non-responders to NAC in LAGC. miR-143-3p, miR-143-5p, and miR-574-3p expression may be used as a potential diagnostic tool in GC patients. The presence of miR-551b-5p may support the correct assessment of a response to NAC in GC via CT.

The RNA world: from experimental laboratory to "in silico" approach. Part 1: User friendly RNA expression databases portals.

Cellular information about "life instruction" is stored, transferred, and modified using different types of RNA molecules. During the last decades, a growing number of RNA data has been generated thanks to the development of microarray chips and next-generation sequencing (NGS) methods. Improvement of bioinformatics contributed to the discovery of many types of new non-coding RNAs (ncRNAs), mostly with regulatory functions that supplemented the knowledge about the world of RNA. All of it, as well as the Human Genome Project (HGP) and the Cancer Genome Atlas (TCGA) project, has resulted in the formation of data storage and analysis portals which are widely used in cancer research and moved science from in vitro to in silico research. In this review we presented and discussed the data storage and analysis portals used by us, such as cBioPortal, UALCAN, ENCORI, and others. During the revision of these sites, we paid attention to data integration, simplicity of analysis, and results visualization, which are important for users without bioinformatic or statistical skills. In our opinion, the RNA analysis online tools will rapidly develop during the next decade and it seems to be a way for personalization of cancer treatment.

Targeting the Hippo Pathway in Cutaneous Melanoma.

Melanoma is the most aggressive form of skin cancer. In the advanced stage of development, it is resistant to currently available therapeutic modalities. Increased invasiveness and metastatic potential depend on several proteins involved in various signal transduction pathways. Hippo signaling plays a vital role in malignant transformation. Dysfunctions of the Hippo pathway initiate the expression of tumor growth factors and are associated with tumor growth and metastasis formation. This review summarizes the recent achievements in studying the role of the Hippo pathway in melanoma pathogenesis and points to the potential specific targets for anti-melanoma therapy.

Diagnostic and prognostic role of long non-coding RNAs (lncRNAs) in metastatic melanoma patients with BRAF gene mutation receiving BRAF and MEK inhibitors.

Melanoma is a cancer with a high incidence rate that, despite the significant development of therapeutic options, still remains a major problem. The identification of biomarkers to select the right therapy for the right patient is one of the possibilities to improve the prognosis of patients. Potentially, the function of biomarkers could be played long non-coding RNAs (lncRNAs). The expression of selected 90 lncRNAs in serum from 30 metastatic melanoma patients with confirmed mutations in the BRAF V600 E or K gene was studied. Serum was collected prior to BRAF and MEK inhibitor therapy. The control group consisted of 16 healthy volunteers. A total of 41 lncRNAs were identified the expression of which differed statistically significantly between the patient group and the healthy volunteers. In addition, it was shown that the expression of HOXA3as (p = 0.033), PRINS (p = 0.036) and RNCR3 (p = 0.045) is higher in patients with the presence of CNS metastases, PFS inhibiting RNA (p = 0.048) is higher among patients with the presence of hepatic metastases, UCA1 (p = 0.008) expression is lower in patients with increased lactate dehydrogenase levels, while HOTAIRM1 (p = 0.044) and E2F4 antisense (p = 0.040) expression is lower in patients over 60 years of age. In addition, patients with high lincRNASFMBT2 expression showed longer median PFS (8.75 vs. 17.5 months, p = 0.0319) and OS (9.75 vs. 38 months (open observation, p = 0.0253). The obtained results require validation on a larger group of patients. If the results are confirmed, the indicated lncRNAs may play an important role as diagnostic and prognostic markers.

Identification of ATM-dependent long non-coding RNAs induced in response to DNA damage.

DNA damage response (DDR) is a complex process, essential for cell survival. Especially deleterious type of DNA damage are DNA double-strand breaks (DSB), which can lead to genomic instability and malignant transformation if not repaired correctly. The central player in DSB detection and repair is the ATM kinase which orchestrates the action of several downstream factors. Recent studies have suggested that long non-coding RNAs (lncRNAs) are involved in DDR. Here, we aimed to identify lncRNAs induced upon DNA damage in an ATM-dependent manner. DNA damage was induced by ionizing radiation (IR) in immortalized lymphoblastoid cell lines derived from 4 patients with ataxia-telangiectasia (AT) and 4 healthy donors. RNA-seq revealed 10 lncRNAs significantly induced 1 h after IR in healthy donors, whereas none in AT patients. 149 lncRNAs were induced 8 h after IR in the control group, while only three in AT patients. Among IR-induced mRNAs, we found several genes with well-known functions in DDR. Gene Set Enrichment Analysis and Gene Ontology revealed delayed induction of key DDR pathways in AT patients compared to controls. The induction and dynamics of selected 9 lncRNAs were confirmed by RT-qPCR. Moreover, using a specific ATM inhibitor we proved that the induction of those lncRNAs is dependent on ATM. Some of the detected lncRNA genes are localized next to protein-coding genes involved in DDR. We observed that induction of lncRNAs after IR preceded changes in expression of adjacent genes. This indicates that IR-induced lncRNAs may regulate the transcription of nearby genes. Subcellular fractionation into chromatin, nuclear, and cytoplasmic fractions revealed that the majority of studied lncRNAs are localized in chromatin. In summary, our study revealed several lncRNAs induced by IR in an ATM-dependent manner. Their genomic co-localization and co-expression with genes involved in DDR suggest that those lncRNAs may be important players in cellular response to DNA damage.

SRY-Related Transcription Factors in Head and Neck Squamous Cell Carcinomas: In Silico Based Analysis.

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer and the fifth cause of cancer-related deaths worldwide with a poor 5-year survival. SOX family genes play a role in the processes involved in cancer development such as epithelial-mesenchymal transition (EMT), the maintenance of cancer stem cells (CSCs) and the regulation of drug resistance. We analyzed the expression of SOX2-OT, SOX6, SOX8, SOX21, SOX30 and SRY genes in HNSCC patients using the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets, to assess their biological role and their potential utility as biomarkers. We demonstrated statistically significant differences in expression between normal and primary tumor tissues for SOX6, SOX8, SOX21 and SOX30 genes and pointed to SOX6 as the one that met the independent diagnostic markers criteria. SOX21 or SRY alone, or the panel of six SRY-related genes, could be used to estimate patient survival. SRY-related genes are positively correlated with immunological processes, as well as with keratinization and formation of the cornified envelope, and negatively correlated with DNA repair and response to stress. Moreover, except SRY, all analyzed genes were associated with a different tumor composition and immunological profiles. Based on validation results, the expression of SOX30 is higher in HPV(+) patients and is associated with patients' survival. SRY-related transcription factors have vast importance in HNSCC biology. SOX30 seems to be a potential biomarker of HPV infection and could be used as a prognostic marker, but further research is required to fully understand the role of SOX family genes in HNSCC.

Angiotensin-converting enzyme inhibitors for ovarian cancer? - a new adjuvant option or a silent trap.

Background: Ovarian cancer is a huge therapeutic and financial problem for which approved treatments have already achieved their limit of efficiency. A cost-effective strategy to extend therapeutic options in this malignancy is drug repurposing aimed at overcoming chemoresistance. Here, angiotensin-converting enzyme inhibitors (ACE-I) are worth considering. Materials and methods: We searched literature for publications supporting the idea of adjuvant application of ACE-Is in ovarian malignancy. Then, we searched The Cancer Genome Atlas databases for relevant alternations of gene expression patterns. We also performed in silico structure-activity relationship evaluation for predicting ACE-Is' cytotoxicity against ovarian cancer cell lines. Finally, we reviewed the potential obstacles in ACE-Is repurposing process. Results: The alternation of angiotensin receptor expression in ovarian cancer translates into poorer patient survival. This confirms the participation of the renin-angiotensin system in ovarian carcinogenesis. In observational studies, ACE-Is were shown synergize with both, platinum-based chemotherapy as well as with antiangiogenic therapy. Consistently, our in silico simulation showed that ACE-Is are probably cytotoxic against ovarian cancer cells. However, the publications on their chemopreventive properties were inconclusive. In addition, some reports correlated ACE-Is use with increased general cancer incidence. We hypothesized that this effect could be associated with mutagenic nitrosamine formation in ACE-Is' pharmaceutical formulations, as was the case with angiotensin receptor blockers (ARBs) and other well-established pharmaceuticals. Conclusions: Available data warrant further research into repositioning ACE-Is to ovarian cancer as chemosensitizers. Prior to this, however, a special research program is needed to detect possible genotoxic contaminants of ACE-Is.

Biological role and diagnostic utility of ribosomal protein L23a pseudogene 53 in cutaneous melanoma.

Background: Skin melanoma is one of the deadliest types of skin cancer and develops from melanocytes. The genetic aberrations in protein-coding genes are well characterized, but little is known about changes in non-coding RNAs (ncRNAs) such as pseudogenes. Ribosomal protein pseudogenes (RPPs) have been described as the largest group of pseudogenes which are dispersed in the human genome. Materials and methids: We looked deeply at the role of one of them, ribosomal protein L23a pseudogene 53 (RPL23AP53), and its potential diagnostic use. The expression level of RPL23AP53 was profiled in melanoma cell lines using real time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and analyzed based on the Cancer Genome Atlas (TCGA) data depending on BRAF status and clinicopathological parameters. Cellular phenotype, which was associated with RPL23AP53 levels, was described based on the REACTOME pathway browser, Gene Set Enrichment Analysis (GSEA) analysis as well as Immune and ESTIMATE Scores. Results: We indicted in vitro changes in RPL23AP53 level depending on a cell line, and based on in silico analysis of TCGA samples demonstrated significant differences in RPL23AP53 expression between primary and metastatic melanoma, as well as correlation between RPL23AP53 and overall survival. No differences depending on BRAF status were observed. RPL23AP53 is associated with several signaling pathways and cellular processes. Conclusions: This study showed that patients with higher expression of RPL23AP53 displayed changed infiltration of lymphocytes, macrophages, and neutrophils compared to groups with lower expression of RPL23AP53. RPL23AP53 pseudogene is differently expressed in melanoma compared with normal tissue and its expression is associated with cellular proliferation. Thus, it may be considered as an indicator of patients' survival and a marker for the immune profile assessment.

Host gene and its guest: short story about relation of long-noncoding MIR31HG transcript and microRNA miR-31.

Epigenetics is the changes in a cellular phenotype without changes in the genotype. This term is not limited only to the modification of chromatin and DNA but also relates to some RNAs, like non-coding RNAs (ncRNAs), both short and long RNAs (lncRNAs) acting as molecular modifiers. Mobile RNAs, as a free form or encapsulated in exosomes, can regulate neighboring cells or be placed in distant locations. It underlines the vast capacity of ncRNAs as epigenetic elements of transmission information and message of life. One of the amazing phenomena is long non-coding microRNA-host-genes (lnc-MIRHGs) whose processed transcripts function as lncRNAs and also as short RNAs named microRNAs (miRNAs). MIR31HG functions as a modulator of important biological and cellular processes including cell proliferation, apoptosis, cell cycle regulation, EMT process, metastasis, angiogenesis, hypoxia, senescence, and inflammation. However, in most cases, the role of MIR31HG is documented only by one study and there is a lack of exact description of molecular pathways implicated in these processes, and for some of them, such as response to irradiation, no studies have been done. In this review, MIR31HG, as an example of lnc-MIRHGs, was described in the context of its known function and its potential uses as a biomarker in oncology.

Vitamin D supplementation increases objective response rate and prolongs progression-free time in patients with advanced melanoma undergoing anti-PD-1 therapy.

BACKGROUND: Vitamin D3 is a prohormone with pleiotropic effects, including modulating the functions of the immune system and may affect the effectiveness of anti-PD-1 treatment in patients with cancer. According to the literature, the potential mechanism of vitamin D's influence on the effectiveness of therapy is most likely related to the amount and activity of tumor-infiltrating lymphocytes. There are data showing the effect of vitamin D on cells regulating the activity of CD8 lymphocytes. METHODS: A total of 200 patients with advanced melanoma were included in the study. All patients received anti-PD-1 immunotherapy (nivolumab or pembrolizumab) as first-line treatment. Serum vitamin D levels were measured in patients both before and every 12 weeks during treatment. Part of the group had vitamin D measured retrospectively from the preserved serum. The other part of the supplementation group was tested prospectively. RESULTS: The response rate in the group with low vitamin D levels and not supplemented was 36.2%, whereas in the group with normal baseline levels or a normal level obtained with supplementation was 56.0% (p = .01). Moreover, progression-free survival in these groups was 5.75 and 11.25 months, respectively (p = .03). In terms of overall survival, there was also a difference in favor of the group with normal vitamin D levels (27 vs. 31.5 months, respectively; p = .39). CONCLUSIONS: In our opinion, maintaining the vitamin D level within the normal range during anti-PD-1 immunotherapy in advanced melanoma patients should be a standard procedure allowing the improvement of treatment outcomes.

The Impact of YRNAs on HNSCC and HPV Infection.

HPV infection is one of the most important risk factors for head and neck squamous cell carcinoma among younger patients. YRNAs are short non-coding RNAs involved in DNA replication. YRNAs have been found to be dysregulated in many cancers, including head and neck squamous cell carcinoma (HNSCC). In this study, we investigated the role of YRNAs in HPV-positive HNSCC using publicly available gene expression datasets from HNSCC tissue, where expression patterns of YRNAs in HPV(+) and HPV(-) HNSCC samples significantly differed. Additionally, HNSCC cell lines were treated with YRNA1-overexpressing plasmid and RNA derived from these cell lines was used to perform a NGS analysis. Additionally, a deconvolution analysis was performed to determine YRNA1's impact on immune cells. YRNA expression levels varied according to cancer pathological and clinical stages, and correlated with more aggressive subtypes. YRNAs were mostly associated with more advanced cancer stages in the HPV(+) group, and YRNA3 and YRNA1 expression levels were found to be correlated with more advanced clinical stages despite HPV infection status, showing that they may function as potential biomarkers of more advanced stages of the disease. YRNA5 was associated with less-advanced cancer stages in the HPV(-) group. Overall survival and progression-free survival analyses showed opposite results between the HPV groups. The expression of YRNAs, especially YRNA1, correlated with a vast number of proteins and cellular processes associated with viral infections and immunologic responses to viruses. HNSCC-derived cell lines overexpressing YRNA1 were then used to determine the correlation of YRNA1 and the expression of genes associated with HPV infections. Taken together, our results highlight the potential of YRNAs as possible HNSCC biomarkers and new molecular targets.

Impact of ramipril nitroso-metabolites on cancer incidence - in silico and in vitro safety evaluation.

Background: Angiotensin-converting enzyme inhibitors (ACE-I) and their pharmacologically related sartans have been associated with an increased cancer incidence in several clinical observations. In 2018, sartans were revealed as being significantly contaminated with nitrosamines. Nitrosamines are potent human mutagens that can be formed ex vivo and, more concerningly, also in vivo from nitrosatable drug precursors. Their formation in sartans may justify the reported cancer risk and, by analogy, this may also apply to ACE-Is. Materials and methods: We investigated a commonly used ACE-I, ramipril (RAM). We checked its susceptibility to in vivo interaction with nitrite, potentially resulting in the generation of mutagenic N-nitrosamines. To that end, in silico simulation of mutagenicity of RAM nitroso-derivatives was performed using VEGA-GUI software. Then, the Nitrosation Assay Procedure was conducted which served as a model of endogenous reaction. The resulting post-nitrosation mixtures were subjected to a bacterial reverse mutation test employing Salmonella typhimurium strains TA98 and TA100 with and without metabolic activation. Results: Our results showed that studied samples did not induce point mutations in the test bacteria, regardless of the catalytic cytochrome activity. Conclusion: We concluded that RAM endogenous nitrosation is not the reason for increased cancer incidence. However, other ACE-Is must be verified in a similar manner.

miRNA in head and neck squamous cell carcinomas: promising but still distant future of personalized oncology.

Head and neck squamous cell carcinoma is one of the most common and fatal cancers worldwide. Lack of appropriate preventive screening tests, late detection, and high heterogeneity of these tumors are the main reasons for the unsatisfactory effects of therapy and, consequently, unfavorable outcomes for patients. An opportunity to improve the quality of diagnostics and treatment of this group of cancers are microRNAs (miRNAs) - molecules with a great potential both as biomarkers and therapeutic targets. This review aims to present the characteristics of these short non-coding RNAs (ncRNAs) and summarize the current reports on their use in oncology focused on medical strategies tailored to patients' needs.

Zinc Finger Proteins in Head and Neck Squamous Cell Carcinomas: ZNF540 May Serve as a Biomarker.

Head and neck squamous cell carcinoma (HNSCC) is one of the ten most common cancers. Most cancer cases originate from alcohol and tobacco consumption. However, studies have demonstrated that human papillomavirus (HPV) infection, particularly HPV-16, may also significantly influence disease progression. The KRAB-ZNF family of genes is involved in epigenetic suppression, and its involvement in carcinogenesis is the subject of extensive studies. The available literature data demonstrate that they may play different roles, both as tumor suppressors and oncogenes. In this study, six ZNF genes, ZFP28, ZNF132, ZNF418, ZNF426, ZNF540, and ZNF880, were tested using several in silico approaches based on the TCGA and GEO datasets. Our analyses indicate that the expression of the analyzed ZNFs was significantly downregulated in tumor tissues and depended on tumor localization. The expression levels of ZNFs differed between HPV-positive vs. HPV-negative patients depending on the clinical-pathological parameters. More specifically, the patients with higher levels of ZNF418 and ZNF540 showed better survival rates than those with a lower expression. In addition, the level of ZNF540 expression in HPV-positive (HPV(+)) patients was higher than in HPV-negative (HPV(-)) patients (p < 0.0001) and was associated with better overall survival (OS). In conclusion, we demonstrate that ZNF540 expression highly correlates with HPV infection, which renders ZNF540 a potential biomarker for HNSCC prognosis and treatment.

Radio-lncRNAs: Biological Function and Potential Use as Biomarkers for Personalized Oncology.

Long non-coding RNAs (lncRNAs) consist of at least 200 nucleotides. Although these molecules do not code proteins, they carry many regulatory functions in normal cells, as well as in cancer cells. For instance, many of these molecules have been previously correlated with tumorigenesis of different cancers and their reaction to various stress factors, such as radiotherapy, chemotherapy, or reactive oxygen species (ROS). The lncRNAs are associated not only with dysregulation in cancers after applied treatment but also with beneficial effects that may be achieved by modulating their expression, often significantly enhancing the patients' outcomes. A multitude of these molecules was previously considered as potential biomarkers of tumor development, progression, or cells' response to radio- or chemotherapy. Irradiation, which is often used in treating numerous cancer types, is not always sufficient due to cells gaining resistance in multiple ways. In this review, studies considering lncRNAs and their reaction to radiotherapy were examined. These molecules were divided regarding their role in specific processes strictly related to irradiation, and their influence on this type of treatment was explained, showing how vast an impact they have on IR-supported combat with the disease. This review aims to shed some light on potential future lncRNA-based biomarkers and therapeutic targets.

C10orf55, CASC2, and SFTA1P lncRNAs Are Potential Biomarkers to Assess Radiation Therapy Response in Head and Neck Cancers.

Long non-coding RNAs have proven to be important molecules in carcinogenesis. Due to little knowledge about them, the molecular mechanisms of tumorigenesis are still being explored. The aim of this work was to study the effect of ionizing radiation on the expression of lncRNAs in head and neck squamous cell carcinoma (HNSCC) in patients responding and non-responding to radiotherapy. The experimental model was created using a group of patients with response (RG, n = 75) and no response (NRG, n = 75) to radiotherapy based on the cancer genome atlas (TCGA) data. Using the in silico model, statistically significant lncRNAs were defined and further validated on six HNSCC cell lines irradiated at three different doses. Based on the TCGA model, C10orf55, C3orf35, C5orf38, CASC2, MEG3, MYCNOS, SFTA1P, SNHG3, and TMEM105, with the altered expression between the RG and NRG were observed. Analysis of pathways and immune profile indicated that these lncRNAs were associated with changes in processes, such as epithelial-to-mesenchymal transition, regulation of spindle division, and the p53 pathway, and differences in immune cells score and lymphocyte infiltration signature score. However, only C10orf55, CASC2, and SFTA1P presented statistically altered expression after irradiation in the in vitro model. In conclusion, the expression of lncRNAs is affected by ionization radiation in HNSCC, and these lncRNAs are associated with pathways, which are important for radiation response and immune response. Potentially presented lncRNAs could be used as biomarkers for personalized radiotherapy in the future. However, these results need to be verified based on an in vitro experimental model to show a direct net of interactions.

Oxidative stress in melanogenesis and melanoma development.

Melanoma is the most aggressive skin cancer, with a growing number of incidents worldwide and with no effective cure in a metastatic stage so far. There are several pathways and processes engaged in melanoma pathogenesis that have been extensively explored in recent years. The emerging evidence suggests that oxidative stress (OS) is highly involved in melanin synthesis and melanoma formation. Melanoma is particularly susceptible to OS due to the involvement of melanin synthesis and UV radiation in the generation of reactive oxygen species. Oxidative stress influences melanoma immunity, the metastatic potential of melanoma cells and their resistance to therapy. In malignant melanocytes, the process of melanogenesis is frequently upregulated, suggesting possible therapeutic targets. This review describes the role of OS in melanin synthesis in melanocytes and explains how it affects melanoma cells. Better knowledge about the mechanisms involved in cancer progression may result in the development of better treatment strategies.

Midsize noncoding RNAs in cancers: a new division that clarifies the world of noncoding RNA or an unnecessary chaos?

Most of the human genome is made out of noncoding RNAs (ncRNAs). These ncRNAs do not code for proteins but carry a vast number of important functions in human cells such as: modification and processing other RNAs (tRNAs, rRNAs, snRNAs, snoRNAs, miRNAs), help in the synthesis of ribosome proteins, initiation of DNA replication, regulation of transcription, processing of pre-messenger mRNA during its maturation and much more. The ncRNAs also have a significant impact on many events that occur during carcinogenesis in cancer cells, such as: regulation of cell survival, cellular signaling, apoptosis, proliferation or even influencing the metastasis process. The ncRNAs may be divided based on their length, into short and long, where 200 nucleotides is the "magic" border. However, a new division was proposed, suggesting the creation of the additional group called midsize noncoding RNAs, with the length ranging from 50-400 nucleotides. This new group may include: transfer RNA (tRNA), small nuclear RNAs (snRNAs) with 7SK and 7SL, small nucleolar RNAs (snoRNAs), small Cajal body-specific RNAs (scaRNAs) and YRNAs. In this review their structure, biogenesis, function and influence on carcinogenesis process will be evaluated. What is more, a question will be answered of whether this new division is a necessity that clears current knowledge or just creates an additional misunderstanding in the ncRNA world?

miR-154 Influences HNSCC Development and Progression through Regulation of the Epithelial-to-Mesenchymal Transition Process and Could Be Used as a Potential Biomarker.

MicroRNAs and their role in cancer have been extensively studied for the past decade. Here, we analyzed the biological role and diagnostic potential of miR-154-5p and miR-154-3p in head and neck squamous cell carcinoma (HNSCC). miRNA expression analyses were performed using The Cancer Genome Atlas (TCGA) data accessed from cBioPortal, UALCAN, Santa Cruz University, and Gene Expression Omnibus (GEO). The expression data were correlated with clinicopathological parameters. The functional enrichment was assessed with Gene Set Enrichment Analysis (GSEA). The immunological profiles were assessed using the ESTIMATE tool and RNAseq data from TCGA. All statistical analyses were performed with GraphPad Prism and Statistica. The study showed that both miR-154-5p and miR-154-3p were downregulated in the HNSCC samples and their expression levels correlated with tumor localization, overall survival, cancer stage, tumor grade, and HPV p16 status. GSEA indicated that individuals with the increased levels of miR-154 had upregulated AKT-MTOR, CYCLIN D1, KRAS, EIF4E, RB, ATM, and EMT gene sets. Finally, the elevated miR-154 expression correlated with better immune response. This study showed that miR-154 is highly involved in HNSCC pathogenesis, invasion, and immune response. The implementation of miR-154 as a biomarker may improve the effectiveness of HNSCC treatment.