The intratumour microbiota and neutrophilic inflammation in squamous cell vulvar carcinoma microenvironment.

BACKGROUND: A causal link between microbiota composition (dysbiosis) and oncogenesis has been demonstrated for several types of cancer. Neutrophils play a role in both immune protection against bacterial threats and carcinogenesis. This study aimed to characterise intratumoral bacteria in vulvar squamous cell carcinoma (VSCC) and their putative effect on neutrophil recruitment and cancer progression. METHODS: Clinical material was obtained from 89 patients with VSCC. Next-generation sequencing (NGS) of 16S rRNA and quantitative polymerase chain reaction (qPCR) were used to detect bacterial species in VSCC. To verify neutrophil activation, CD66b expression in tumour specimens was analysed by immunohistochemistry (IHC). Subsequently, IHC was applied to detect the main neutrophil serine proteases (NSPs), cathepsin G (CTSG), neutrophil elastase (ELANE), and proteinase 3 (PRTN3) in VSCC. RESULTS: Fusobacterium nucleatum and Pseudomonas aeruginosa were identified as tumour-promoting bacteria, and their presence was found to be associated with a shorter time to progression in VSCC patients. Furthermore, high abundance of CD66b, the neutrophil activation marker, in VSCC samples, was found to relate to poor survival of patients with VSCC. The selected NSPs were shown to be expressed in vulvar tumours, also within microabscess. The increased numbers of microabscesess were correlated with poor survival in VSCC patients. CONCLUSIONS: Our results show that neutrophilic inflammation seem to be permissive for tumour-promoting bacteria growth in VSCC. The findings provide new therapeutic opportunities, such as based on shifting the balance of neutrophil populations to those with antitumorigenic activity and on targeting NSPs produced by activated neutrophils at the inflammation sites.

The Importance of the Immune System and Molecular Cell Signaling Pathways in the Pathogenesis and Progression of Lung Cancer.

Lung cancer is a disease that in recent years has become one of the greatest threats to modern society. Every year there are more and more new cases and the percentage of deaths caused by this type of cancer increases. Despite many studies, scientists are still looking for answers regarding the mechanisms of lung cancer development and progression, with particular emphasis on the role of the immune system. The aim of this literature review was to present the importance of disorders of the immune system and the accompanying changes at the level of cell signaling in the pathogenesis of lung cancer. The collected results showed that in the process of immunopathogenesis of almost all subtypes of lung cancer, changes in the tumor microenvironment, deregulation of immune checkpoints and abnormalities in cell signaling pathways are involved, which contribute to the multistage and multifaceted carcinogenesis of this type of cancer. We, therefore, suggest that in future studies, researchers should focus on a detailed analysis of tumor microenvironmental immune checkpoints, and to validate their validity, perform genetic polymorphism analyses in a wide range of patients and healthy individuals to determine the genetic susceptibility to lung cancer development. In addition, further research related to the analysis of the tumor microenvironment; immune system disorders, with a particular emphasis on immunological checkpoints and genetic differences may contribute to the development of new personalized therapies that improve the prognosis of patients.

CD276 as a Candidate Target for Immunotherapy in Medullary Thyroid Cancer.

Medullary thyroid cancer (MTC) is a rare malignancy, and the treatment of metastatic MTC is challenging. In previous work, immune profiling (RNA-Seq) of MTC identified CD276 as a potential target for immunotherapy. CD276 expression was 3-fold higher in MTC cells than in normal tissues. Paraffin blocks from patients with MTC were analyzed by immunohistochemistry to confirm the results of RNA-Seq. Serial sections were incubated with anti-CD276 antibody, and scored according to staining intensity and the percentage of immunoreactive cells. The results showed that CD276 expression was higher in MTC tissues than in controls. A lower percentage of immunoreactive cells correlated with the absence of lateral node metastasis, lower levels of calcitonin after surgery, no additional treatments, and remission. There were statistically significant associations of intensity of immunostaining and percentage of CD276 immunoreactive cells with clinical factors and the course of the disease. These results suggest that targeting this immune checkpoint molecule CD276 could be a promising strategy for the treatment of MTC.

Hypogelsolinemia and Decrease in Blood Plasma Sphingosine-1-Phosphate in Patients Diagnosed with Severe Acute Pancreatitis.

BACKGROUND: Acute pancreatitis (AP) is a frequent hospitalization cause of patients suffering from gastrointestinal disorders. Gelsolin has an ability to bind bioactive lipids including different sphingolipids engaged in inflammatory response. Importantly, hypogelsolinemia was observed in patients with different states of acute and chronic inflammation. AIMS: The aim of the present study was to assess the interplay of blood plasma gelsolin and blood plasma sphingosine-1-phosphate (S1P) concentration in patients diagnosed with acute pancreatitis. MATERIALS AND METHODS: To assess the concentration of gelsolin and S1P, immunoblotting and HPLC technique were employed, respectively. Additionally, the concentrations of amylase, lipase, C-reactive protein (CRP), procalcitonin (PCT) and the number of white blood cells (WBC) and platelet (PLT) were recorded. RESULTS: We found that both pGSN and S1P concentrations in the plasma of the AP patients were significantly lower (pGSN ~ 15-165 mg/L; S1P ~ 100-360 pmol/mL) when compared to the levels of pGSN and S1P in a control group (pGSN ~ 130-240 mg/L; S1P ~ 260-400 pmol/mL). Additionally, higher concentrations of CRP, WBC, amylase and lipase were associated with low level of gelsolin in the blood of AP patients. No correlations between the level of PCT and PLT with gelsolin concentration were noticed. CONCLUSION: Plasma gelsolin and S1P levels decrease during severe acute pancreatitis. Simultaneous assessment of pGSN and S1P can be useful in development of more accurate diagnostic strategies for patients with severe acute pancreatitis.

Sphingosine-1-Phosphate-Triggered Expression of Cathelicidin LL-37 Promotes the Growth of Human Bladder Cancer Cells.

It has been proven that tumour growth and progression are regulated by a variety of mediators released during the inflammatory process preceding the tumour appearance, but the role of inflammation in the development of bladder cancer is ambiguous. This study was designed around the hypothesis that sphingosine-1-phosphate (S1P), as a regulator of several cellular processes important in both inflammation and cancer development, may exert some of the pro-tumorigenic effects indirectly due to its ability to regulate the expression of human cathelicidin (hCAP-18). LL-37 peptide released from hCAP-18 is involved in the development of various types of cancer in humans, especially those associated with infections. Using immunohistological staining, we showed high expression of hCAP-18/LL-37 and sphingosine kinase 1 (the enzyme that forms S1P from sphingosine) in human bladder cancer cells. In a cell culture model, S1P was able to stimulate the expression and release of hCAP-18/LL-37 from human bladder cells, and the addition of LL-37 peptide dose-dependently increased their proliferation. Additionally, the effect of S1P on LL-37 release was inhibited in the presence of FTY720P, a synthetic immunosuppressant that blocks S1P receptors. Together, this study presents the possibility of paracrine relation in which LL-37 production following cell stimulation by S1P promotes the development and growth of bladder cancer.

Biocompatible Materials in Otorhinolaryngology and Their Antibacterial Properties.

For decades, biomaterials have been commonly used in medicine for the replacement of human body tissue, precise drug-delivery systems, or as parts of medical devices that are essential for some treatment methods. Due to rapid progress in the field of new materials, updates on the state of knowledge about biomaterials are frequently needed. This article describes the clinical application of different types of biomaterials in the field of otorhinolaryngology, i.e., head and neck surgery, focusing on their antimicrobial properties. The variety of their applications includes cochlear implants, middle ear prostheses, voice prostheses, materials for osteosynthesis, and nasal packing after nasal/paranasal sinuses surgery. Ceramics, such as as hydroxyapatite, zirconia, or metals and metal alloys, still have applications in the head and neck region. Tissue engineering scaffolds and drug-eluting materials, such as polymers and polymer-based composites, are becoming more common. The restoration of life tissue and the ability to prevent microbial colonization should be taken into consideration when designing the materials to be used for implant production. The authors of this paper have reviewed publications available in PubMed from the last five years about the recent progress in this topic but also establish the state of knowledge of the most common application of biomaterials over the last few decades.

Immunological Prognostic Factors in Multiple Myeloma.

Multiple myeloma (MM) is a plasma cell neoplasm characterized by an abnormal proliferation of clonal, terminally differentiated B lymphocytes. Current approaches for the treatment of MM focus on developing new diagnostic techniques; however, the search for prognostic markers is also crucial. This enables the classification of patients into risk groups and, thus, the selection of the most optimal treatment method. Particular attention should be paid to the possible use of immune factors, as the immune system plays a key role in the formation and course of MM. In this review, we focus on characterizing the components of the immune system that are of prognostic value in MM patients, in order to facilitate the development of new diagnostic and therapeutic directions.

Analysis of mutations of PARP1, RNF213, PAX8, KMT2C, MTRR in malignant mesothelioma of testicular tunica vaginalis testis.

Molecular next gene sequencing was used to evaluate mutations in 409 common mutated cancer-related genes in malignant mesothelioma of tunica vaginalis testis (MMTVT) of 81-year-old man. Multifocal papillary-solid areas contained necrosis among highly cellular fields with multiple mitoses. It was positive for WT1, CKAE1/AE3, calretinin, CK7 with negativity for CK5, PSA, TTF-1. Following mutations were revealed in PARP1 (NM_001618: c.2285TG, p.K135R), MTRR (NM_024010: c.147A>G, p.I49M) and two sorts of mutations in structure of KMT2C gene (NM_170606: c.2447_2448insA (c.2447dupA), p.Y816fs and NM_170606: c.1042G>A, p.D348N) for the first time in MMTVT.

Review on significance of GDNF, PTCH1 and RNF213 in chromophobe renal cell carcinoma illustrated by the case of 71-years-old man.

Here we review the role of GDNF, PTCH1, RNF213 illustrated by a case of renal cell carcinoma, chromophobe type (pT2a 8th pTNM edition) of the left kidney of 71-year-old man. Status of potential hotspots in 409 tumor genes were studied by means of next generation sequencing (NGS) technology (IonTorrent - Thermo Fisher Scientific, USA) using Ion AmpliSeq™ Comprehensive Cancer Panel. Next-generation sequencing (NGS) revealed mutations of GDNF (NM_001190468: c. 328C>T, p.R110W, allelic frequency 46%), PTCH1 (NM_001083607:c. 2969C

Poorly differentiated thyroid cancer in the context of the revised 2015 American Thyroid Association Guidelines and the Updated American Joint Committee on Cancer/Tumor-Node-Metastasis Staging System (eighth edition).

OBJECTIVE: Poorly differentiated thyroid cancer (PDTC) is a rare, but aggressive thyroid cancer (TC) and a main cause of death from non-anaplastic follicular cell-derived TC. Assessing the risk of PDTC-related death and the risk of recurrence is important for clinicians. The recent American Thyroid Association (ATA) 2015 guidelines and the updated 8th edition of the American Joint Committee on Cancer/Tumor-Node-Metastasis (AJCC/TNM) staging system should support clinicians in the management approach to PDTC patients. PATIENTS: Forty-six consecutive PDTC patients treated in a single oncologic centre, 2000-2017. MEASUREMENTS: Retrospective analysis of TNM stage, initial risk, response-to-therapy categories, follow-up and final disease status incorporating the ATA 2015 criteria and the 8th AJCC/TNM staging system. Disease-specific survival (DSS) using the Kaplan-Meier method. RESULTS: Of the 46 PDTC 21 (45.6%) were ATA high risk (HR), 22 (47.8%), 17 (37%) and seven (15.2%) were TNM stages I, II, and III-IV, respectively. During a median follow-up of 55.5 months, two (4.3%) patients were recurrent, 18 (39.1%) died of PDTC. The 5-/10-year DSS were 65/57%, respectively. According to the AJCC/TNM, the 5-/10-year DSS of I, II, and III-IV stage were 83/83%; 77/55%, and 0/0%, respectively. According to the 2015 ATA initial risk, the 5-/10-year DSS were 91/72% for ATA intermediate risk and 38/38% for ATA HR patients. CONCLUSIONS: In PDTC patients, the updated AJCC/TNM staging system accurately predicts a high risk of death in stage III-IV, whereas it seems to be inadequate for predicting a very low or low risk of death expected for differentiated TC in stage I-II. The ATA initial HR may be also used to predict a high risk of PDTC-related death.

Hypogelsolinemia in Patients Diagnosed with Acute Myeloid Leukemia at Initial Stage of Sepsis.

BACKGROUND Gelsolin (GSN) is an actin-binding and PIP2/Ca²âº-regulated protein found in the cytoplasm and blood plasma. Hypogelsolinemia occurs in a wide range of traumatic injuries and inflammatory reactions. We hypothesize that blood GSN levels will be altered in patients diagnosed with acute myeloid leukemia (AML) that develop sepsis, and assessment of GSN concentration will be a useful marker to determine their clinical outcome. To achieve this task, we evaluated the plasma gelsolin concentration in blood samples collected from patients diagnosed with acute myeloid leukemia (AML) at initial stages of sepsis. MATERIAL AND METHODS To assess if AML patients might be at risk of sepsis, a SOFA score was determined. Plasma gelsolin concentration was evaluated using an immunoblotting technique. RESULTS We found that GSN concentration in the blood of the AML group with developing sepsis was significantly lower (32±41 µg/ml; p<0.05) compared to the AML group (65±35 µg/ml) and control group (176±37 µg/ml; p<0.001). Additionally, low gelsolin concentration in the blood of AML patients developing sepsis was associated with a high SOFA score. A decrease of GSN concentration in the blood of AML subjects with developing sepsis suggests that GSN level in blood reflects not only chronic inflammation stage associated with leukemia, but that GSN depletion also manifests the inflammation associated with sepsis development. CONCLUSIONS The results presented here suggest the possible utility of GSN evaluation for diagnostic purposes. Overall, these data support the that reversing plasma GSN deficiency might be a possible new strategy in sepsis treatment.

Somatic mutations in BRCA1&2 in 201 unselected ovarian carcinoma samples - single institution study.

Ovarian cancer (OC) is the most lethal among gynecologic malignancies worldwide. Unfortunately, in around 70% of cases cancer is diagnosed in late stages (III-IV) which decreases the 5-year survival rate to 25%. The standard of care in ovarian cancer is debulking surgery followed by chemotherapy regimens based on platinum salts. Since 2014 PARP inhibitors became available for OC patients with germline or/and somatic mutations in BRCA1/2, including maintenance therapy. BRCA1/2 Next Generation Sequencing (NGS)-based analysis of formalin-fixed paraffin-embedded (FFPE) ovarian cancer samples becomes the standard of care. The aim of the present study was to evaluate the frequency of mutations in 201 unselected ovarian cancer tissues using the NGS method. In total, pathogenic mutations in both genes were detected in 24% (49/201) of the ovarian cancer cases tested. For 41 patients the results of testing of DNA isolated from blood sample revealed that 17% (35/201) mutations were germline origin, whereas 3% (6/201) mutations were somatic. In 4% (8/201) cases blood sample was inaccessible. The presence of pathogenic mutations was correlated with younger age at diagnosis and serous subtype. Close cooperation between many specialists (gynecologist, pathologist, oncologist, clinical genetics and molecular biologist) is indispensable for efficient and on-time BRCA1/2 ovarian tumor tissue testing.

Somatic mutation profiling of vulvar cancer: Exploring therapeutic targets.

BACKGROUND: Vulvar squamous cell carcinoma (VSCC) constitutes over 90% of vulvar cancer. Its pathogenesis can follow two different pathways; high risk human papillomavirus (hrHPV)-dependent and HPV-independent. Due to the rarity of VSCC, molecular mechanisms underlying VSCC development remain largely unknown. The study aimed to identify pathogenic mutations implicated in the two pathways of VSCC development. METHODS: Using next generation sequencing, 81 VSCC tumors, 52 hrHPV(+) and 29 hrHPV(-), were screened for hotspot mutations in 50 genes covered by the Ion AmpliSeq Cancer Hotspot Panel v2 Kit (Thermo Fisher Scientific). RESULTS: Mutations of TP53 (46% and 41%, of hrHPV(+) and hrHPV(-) cases respectively) and CDKN2A (p16) (25% and 21%, of hrHPV(+) and hrHPV(-) cases respectively) were the most common genetic alterations identified in VSCC tumors. Further mutations were identified in PIK3CA, FBXW7, HRAS, FGFR3, STK11, AKT1, SMAD4, FLT3, JAK3, GNAQ, and PTEN, albeit at low frequencies. Some of the identified mutations may activate the PI3K/AKT/mTOR pathway. The activation of mTOR was confirmed in the vast majority of VSCC samples by immunohistochemical staining. CONCLUSIONS: Detecting pathogenic mutations in 13/50 genes examined at comparable frequencies in hrHPV(+) and hrHPV(-) tumors suggest that genetic mechanisms of the two routes of VSCC pathogenesis may be similar, despite being initiated from different premalignant lesions. Importantly, our data provide a rationale for new anti-VSCC therapies targeting the PI3K/AKT/mTOR pathway.

Anaerobic bacteria growth in the presence of cathelicidin LL-37 and selected ceragenins delivered as magnetic nanoparticles cargo.

BACKGROUND: Cationic antibacterial peptides (CAPs) and synthetic molecules mimicking the amphiphilic structure of CAPs, such as ceragenins, are promising compounds for the development of new antimicrobials. RESULTS: We tested the in vitro activity of ceragenins CSA-13 and CSA-131 against several anaerobic bacteria including Bacteroides spp. and Clostridium difficile. We compared results to the activity of cathelicidin LL-37, metronidazole and nanosystems developed by attachment of CSA-13 and CSA-131 to magnetic nanoparticles (MNPs). The antibacterial effect was tested using killing assay and modified CLSI broth microdilution assay. Ceragenins CSA-13 and CSA-131 displayed stronger bactericidal activity than LL-37 or metronidazole against all of the tested bacterial strains. Additionally CSA-131 revealed an enhanced ability to prevent the formation of Bacteroides fragilis and Propionibacterium acnes biofilms. CONCLUSIONS: These data confirmed that ceragenins display antimicrobial activity against a broad range of microorganisms including anaerobic bacteria and deserve further investigations as compounds serving to develop new treatment against anaerobic and mixed infections.

Response to therapy of papillary thyroid cancer of known BRAF status.

OBJECTIVE: A dynamic risk stratification with modified initial estimated risk based on response to therapy and disease course is one of the crucial changes adopted recently by the American Thyroid Association (ATA). This approach focuses on an individualized risk-adapted approach to the management of differentiated thyroid cancer. The BRAF V600E mutation is the most common genetic alteration in papillary thyroid cancer (PTC). However, the prognostic value of this mutation remains unclear. The aim of this study was to examine the relation between the BRAF V600E status in PTC and all ATA response-to-therapy categories, as well as the recurrence and persistence of both biochemical disease and structural disease. PATIENTS: Unselected PTC cases with known BRAF status diagnosed from 2000 to 2013 and actively monitored at one institution (n=723) were reviewed retrospectively. The association between the BRAF V600E mutation and clinicopathological characteristics, ATA 2015 response-to-therapy category, recurrence after a period of no evidence of disease (NED) and persistent biochemical or structural disease, was analysed. RESULTS: BRAF V600E was found in 65.7% (475/723) of PTC cases. Although BRAF mutation status correlated significantly with certain clinicopathological prognostic factors, there was no correlation with any of the response-to-therapy categories. Recurrences and persistent biochemical or structural disease were not associated with BRAF status. CONCLUSIONS: Our data are consistent with those of other studies reporting a positive relation between BRAF V600E mutation and poor prognostic factors in PTC; however, the BRAF status did not significantly correlate with a response to therapy.

Normalizers for microRNA quantification in plasma of patients with vulvar intraepithelial neoplasia lesions and vulvar carcinoma.

The role of circulating microRNAs as a promising tool for diagnosing cancer and monitoring anticancer therapies has been widely studied in the past decades. To date, no suitable reference microRNAs for normalizing quantitative real-time polymerase chain reaction assays has been identified in vulvar intraepithelial neoplasia lesions and vulvar squamous cell carcinoma. The purpose of this study was to select appropriate references for gene expression studies in plasma of patients with these lesions. Expression levels of six microRNAs-hsa-miR-425-5p, hsa-miR-191-5p, hsa-miR-93-5p, hsa-miR-423-5p, hsa-miR-103a-3p, and hsa-miR-16-5p-were analyzed by quantitative reverse transcription polymerase chain reaction in plasma samples obtained from 17 patients with vulvar intraepithelial neoplasia lesion and 27 patients with vulvar squamous cell carcinoma. The expression stability of these candidate normalizers was assayed using geNorm algorithm. hsa-miR-93-5p was revealed as the most stably expressed reference in plasma samples of both vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma patients. The results pointed at hsa-miR-93-5p and hsa-miR-425-5p as microRNAs that retained the greatest robustness in plasma of vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma patients, respectively. Our work is the first report on reference microRNA selection for quantitative real-time polymerase chain reaction applications in vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma. The candidate microRNA stability values for the two types of lesions are provided and might serve for normalization of the future novel microRNA biomarkers in these rare entities.

Unexpected profile of sphingolipid contents in blood and bone marrow plasma collected from patients diagnosed with acute myeloid leukemia.

BACKGROUND: Impaired apoptotic pathways in leukemic cells enable them to grow in an uncontrolled way. Moreover, aberrations in the apoptotic pathways are the main factor of leukemic cells drug resistance. METHODS: To assess the presence of potential abnormalities that might promote dysfunction of leukemic cells growth, HPLC system was used to determine sphingosine (SFO), sphinganine (SFA), sphingosine-1-phosphate (S1P) and ceramide (CER) concentration in the blood collected from patients diagnose with acute myeloblastic leukemia (AML; n = 49) and compare to values of control (healthily) group (n = 51). Additionally, in AML group concentration of SFO, SFA, S1P and CER was determined in bone marrow plasma and compared to respective values in blood plasma. The concentration of S1P and CER binding protein - plasma gelsolin (GSN) was also assessed in collected samples using immunoblotting assay. RESULTS: We observed that in AML patients the average SFO, SFA and CER concentration in blood plasma was significantly higher (p < 0.001) compare to control group, when blood plasma S1P concentration was significantly lower (p < 0.001). At the same time the CER/S1P ratio in AML patient (44.5 ± 19.4) was about 54% higher compare to control group (20.9 ± 13.1). Interestingly the average concentration of S1P in blood plasma (196 ± 13 pmol/ml) was higher compare to its concentration in plasma collected from bone marrow (154 ± 21 pmol/ml). CONCLUSIONS: We hypothesize that changes in profile of sphingolipids concentration and some of their binding protein partners such as GSN in extracellular environment of blood and bone marrow cells in leukemic patients can be targeted to develop new AML treatment method(s).

Sphingosine-1-Phosphate Metabolism and Its Role in the Development of Inflammatory Bowel Disease.

Beyond their role as structural molecules, sphingolipids are involved in many important cellular processes including cell proliferation, apoptosis, inflammation, and migration. Altered sphingolipid metabolism is observed in many pathological conditions including gastrointestinal diseases. Inflammatory bowel disease (IBD) represents a state of complex, unpredictable, and destructive inflammation of unknown origin within the gastrointestinal tract. The mechanisms explaining the pathophysiology of IBD involve signal transduction pathways regulating gastro-intestinal system's immunity. Progressive intestinal tissue destruction observed in chronic inflammation may be associated with an increased risk of colon cancer. Sphingosine-1-phosphate (S1P), a sphingolipid metabolite, functions as a cofactor in inflammatory signaling and becomes a target in the treatment of IBD, which might prevent its conversion to cancer. This paper summarizes new findings indicating the impact of (S1P) on IBD development and IBD-associated carcinogenesis.

The role of interleukin 15 in neoplasia.

Interleukin 15 is a pleiotropic cytokine of the four α helix bundle family. Binding to a heterotrimeric receptor complex, which consists of a unique, high affinity IL­15Rα­chain and IL-2/IL-15Rß and IL­2Rγ chains, IL­15 activates signaling pathways leading to activation and proliferation of T and B cells, as well as natural killer cells. At the same time, IL­15 protects effector cells from T regulatory cells and does not induce immune tolerance. The significant regulatory action of IL­15 on the immune system provides new opportunities for development of anti­cancer therapies. As documented in many experiments using different tumor models, IL­15 enhances antitumor effects. To improve the efficiency of IL­15, several strategies, including combination with other anti­cancer therapies such as chemotherapy, additional use of antibodies (anti­PD­L1, anti­CTLA­4, anti­CD40), or other cytokines, have been evaluated. Increased anti­tumor activity can also be obtained by using IL­15 agonists. However, acting as a growth factor for immune cells but also for tumor cells, IL­15 may promote their proliferation, survival and dissemination. Of significance seems the role of IL­15 in the pathogenesis of hematological malignancies, which is due to the involvement in the proliferation and differentiation of NK, T and B cells. Currently, several experimental strategies are available to block biological activity of IL­15. Among compounds inhibiting the activity of IL­15 are not only monoclonal antibodies interacting directly with the cytokine or with IL­15R subunits, but also mutant forms of IL­15 and protein constructs.

Frequency and clinicopathologic profile of PIK3CA mutant GISTs: molecular genetic study of 529 cases.

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors usually driven by the mutational activation of receptor tyrosine kinases, KIT, or PDGFRA. Oncogenic activation of phosphatidylinositide-3-kinase (PI3K), a downstream effector in the KIT signaling pathway, has been identified in different types of cancer, with the PI3K 110α subunit encoded by PIK3CA being a common mutational target. In this study, the mutational hotspot in the PIK3CA kinase domain encoded by exon 20 was evaluated in 529 imatinib-naive GISTs using PCR amplification and Sanger sequencing. Eight mutations (two co-existing in one tumor) were identified. Subsequently, The cobas PIK3CA Mutation Test was employed to evaluate mutational hotspots in exons 1, 4, 7, and 9 in 119 PIK3CA exon 20-wild type tumors. In two cases, mutations in exons 1 and 9 were identified. In one GIST, previously undetected by Sanger sequencing, the exon 20 mutation was discovered. Altogether, eight primary and two metastatic GISTs carried PIK3CA mutations. The size of primary PIK3CA-mutant GISTs was ≥14 cm (mean size 17 cm), and mitotic activity varied from 0 to 72 per 50HPF (mean 5/50HPF). Follow-up data showed short survival in 6 of 7 studied cases. Detection of PIK3CA mutations in large or metastatic KIT-mutant GISTs may suggest that PIK3CA-mutant clones have a proliferative advantage during disease progression. Tyrosine kinase inhibitors have been successfully used in GIST treatment. However, resistance frequently develops due to secondary KIT mutations or activation of downstream to KIT signaling pathways, such as the PI3K/AKT/mTOR pathway. PIK3CA mutations similar to the ones detected in GISTs have been shown to cause such activation. Therefore, genotyping of PIK3CA in GISTs might help to pinpoint primary and metastatic tumors with the potential to develop resistance to tyrosine kinase inhibitors and guide therapy with PI3K inhibitors.