Molecular profile is a strong predictor of the pattern of recurrence in patients with endometrial cancer.

OBJECTIVES: To investigate the pattern of first recurrence of disease in patients with endometrial cancer according to molecular classification, and to assess the independent role of molecular profiling in each type of failure. METHODS: Retrospective single-center study including patients diagnosed with endometrial cancer stage I-IVB (International Federation of Gynecology and Obstetrics 2009) between December 1994 and May 2022, who underwent primary surgical treatment and had a complete molecular profile. First recurrence was classified as isolated or multiple, and as vaginal, pelvic, peritoneal, nodal, and distant according to its location. The log-rank test and univariate and multivariate adjusted Cox regression models were used for comparison between groups. RESULTS: A total of 658 patients were included. Recurrence was observed in 122 patients (18.5%) with a recurrence rate of 12.4% among mismatch-repair deficient tumors, 14.5% among non-specific molecular profile, 2.1% among POLE-mutated, and 53.7% among p53-abnormal tumors. Recurrences were found to be isolated in 80 (65.6%) and multiple in 42 (34.4%) patients, with no differences in molecular subtype (p=0.92). Patients with p53-abnormal tumors had a recurrence mainly as distant (28.4%) and peritoneal (21.1%) disease, while patients with non-specific molecular profile tumors presented predominantly with distant failures (10.3%), and mismatch-repair deficient tumors with locoregional recurrences (9.4%).On multivariate analysis, p53-abnormal molecular profile was the only independent risk factor for peritoneal failure (OR=8.54, 95% CI 2.0 to 36.3). Vaginal recurrence was independently associated with p53-abnormal molecular profile (OR=6.51, 95% CI 1.1 to 37.4) and lymphovascular space invasion. p53-abnormal and non-specific molecular profiles were independent predictors for distant recurrence (OR=3.13, 95% CI 1.1 to 8.7 and OR=2.35, 95% CI 1.1 to 5.0, respectively), along with lymphovascular space invasion and high-grade tumors. Molecular profile was not independently associated with pelvic and nodal recurrences. CONCLUSIONS: Endometrial cancer featured different patterns of recurrence depending on the molecular profile. p53-abnormal molecular profiling was the only independent risk factor for peritoneal relapse, while non-specific molecular profile showed a strong association with distant failures.

KLRG1 expression on natural killer cells is associated with HIV persistence, and its targeting promotes the reduction of the viral reservoir.

Human immunodeficiency virus (HIV) infection induces immunological dysfunction, which limits the elimination of HIV-infected cells during treated infection. Identifying and targeting dysfunctional immune cells might help accelerate the purging of the persistent viral reservoir. Here, we show that chronic HIV infection increases natural killer (NK) cell populations expressing the negative immune regulator KLRG1, both in peripheral blood and lymph nodes. Antiretroviral treatment (ART) does not reestablish these functionally impaired NK populations, and the expression of KLRG1 correlates with active HIV transcription. Targeting KLRG1 with specific antibodies significantly restores the capacity of NK cells to kill HIV-infected cells, reactivates latent HIV present in CD4+ T cells co-expressing KLRG1, and reduces the intact HIV genomes in samples from ART-treated individuals. Our data support the potential use of immunotherapy against the KLRG1 receptor to impact the viral reservoir during HIV persistence.

Endometrial adenocarcinoma recurring in the lung: impact of molecular profile and role of local therapies on prognosis.

OBJECTIVES: The objective of our study was to describe the characteristics of patients with endometrial cancer diagnosed with a first recurrence involving the lung, and to describe the prognostic role of the molecular profile. We also aimed to describe the prognostic outcomes after local treatment of recurrence (resection of lung metastases or stereotactic body radiation therapy) in a group of patients with isolated lung recurrence. METHODS: This was a retrospective, single-center study between June 1995 and July 2021. The study included patients diagnosed with a first recurrence of endometrial cancer involving the lung. We defined two groups of patients: patients with isolated lung recurrence (confined to the lung) and patients with multisystemic recurrence (in the lung and other locations). RESULTS: Among 1413 patients diagnosed with endometrial cancer in stage IA to IVA of the International Federation of Gynecology and Obstetrics (FIGO) 2009, 64 (4.5%) patients had a first recurrence involving the lung. Of these, 15 (39.1%) were of a non-specific molecular profile, 16 (25%) were p53-abnormal, 15 (23.4%) were mismatch-repair deficient, and 0% POLE-mutated. P53-abnormal patients had the shortest 3 year progression-free survival after recurrence and those with mismatch-repair deficient had the longest 3 year progression-free survival (14.3% (range; 1.6-40.3) and 47.6% (range; 9.1-79.5) respectively, p=0.001). We found no differences on overall survival after recurrence by molecular profile. Thirty-one of 64 (48.4%) patients had an isolated recurrence in the lung, and 16 (25%) patients received local treatment. When comparing patients with isolated lung recurrence, locally treated patients had a longer median progression-free survival than patients treated systemically (41.9 (range, 15.4-NA) vs 7.8 (range, 7.2-10.6) months respectively, p=0.029), a complete response rate of 80% for stereotactic body radiation therapy and a complete resection of 90.9% for surgery. CONCLUSION: Although few patients will benefit from local treatment (stereotactic body radiation therapy or resection) after a recurrence involving the lung, local therapies might be considered as an option in oligometastatic lung recurrences as they achieve high local control rates and better oncological outcomes than systemic treatment alone.

Peripheral T-cell lymphoma with a T follicular-helper phenotype: A different entity? Results of the Spanish Real-T study.

Nodal peripheral T-cell lymphoma (PTCL) with a T follicular helper phenotype (PTCL-TFH) is a new type of PTCL. We aimed to define its clinical characteristics and prognosis compared to PTCL not otherwise specified (PTCL-NOS) and angioimmunoblastic T-cell lymphoma (AITL). This retrospective observational study included 175 patients diagnosed with PTCL between 2008 and 2013 in 13 Spanish sites. Patient diagnosis was centrally reviewed, and patients were reclassified according to the World Health Organization (WHO) 2016 criteria: 21 patients as PTCL-NOS, 55 as AITL and 23 as PTCL-TFH. Median follow-up was 56.07 months (95% CI 38.7-73.4). Progression-free survival (PFS) and overall survival (OS) were significantly higher in patients with PTCL-TFH than in those with PTCL-NOS and AITL (PFS, 24.6 months vs. 4.6 and 7.8 months, respectively, p = 0.002; OS, 52.6 months vs. 10.0 and 19.3 months, respectively, p < 0.001). Histological diagnosis maintained an independent influence on both PFS (hazard ratio [HR] 4.1 vs. PTCL-NOS, p = 0.008; HR 2.6 vs. AITL, p = 0.047) and OS (HR 5.7 vs. PTCL-NOS, p = 0.004; HR 2.6 vs. AITL, p = 0.096), regardless of the International Prognostic Index. These results suggest that PTCL-TFH could have more favourable features and prognosis than the other PTCL subtypes, although larger series are needed to corroborate these findings.

A combination of molecular and clinical parameters provides a new strategy for high-grade serous ovarian cancer patient management.

BACKGROUND: High-grade serous carcinoma (HGSC) is the most common and deadly subtype of ovarian cancer. Although most patients will initially respond to first-line treatment with a combination of surgery and platinum-based chemotherapy, up to a quarter will be resistant to treatment. We aimed to identify a new strategy to improve HGSC patient management at the time of cancer diagnosis (HGSC-1LTR). METHODS: A total of 109 ready-available formalin-fixed paraffin-embedded HGSC tissues obtained at the time of HGSC diagnosis were selected for proteomic analysis. Clinical data, treatment approach and outcomes were collected for all patients. An initial discovery cohort (n = 21) were divided into chemoresistant and chemosensitive groups and evaluated using discovery mass-spectrometry (MS)-based proteomics. Proteins showing differential abundance between groups were verified in a verification cohort (n = 88) using targeted MS-based proteomics. A logistic regression model was used to select those proteins able to correctly classify patients into chemoresistant and chemosensitive. The classification performance of the protein and clinical data combinations were assessed through the generation of receiver operating characteristic (ROC) curves. RESULTS: Using the HGSC-1LTR strategy we have identified a molecular signature (TKT, LAMC1 and FUCO) that combined with ready available clinical data (patients' age, menopausal status, serum CA125 levels, and treatment approach) is able to predict patient response to first-line treatment with an AUC: 0.82 (95% CI 0.72-0.92). CONCLUSIONS: We have established a new strategy that combines molecular and clinical parameters to predict the response to first-line treatment in HGSC patients (HGSC-1LTR). This strategy can allow the identification of chemoresistance at the time of diagnosis providing the optimization of therapeutic decision making and the evaluation of alternative treatment strategies. Thus, advancing towards the improvement of patient outcome and the individualization of HGSC patients' care.

Detection of early seeding of Richter transformation in chronic lymphocytic leukemia.

Richter transformation (RT) is a paradigmatic evolution of chronic lymphocytic leukemia (CLL) into a very aggressive large B cell lymphoma conferring a dismal prognosis. The mechanisms driving RT remain largely unknown. We characterized the whole genome, epigenome and transcriptome, combined with single-cell DNA/RNA-sequencing analyses and functional experiments, of 19 cases of CLL developing RT. Studying 54 longitudinal samples covering up to 19 years of disease course, we uncovered minute subclones carrying genomic, immunogenetic and transcriptomic features of RT cells already at CLL diagnosis, which were dormant for up to 19 years before transformation. We also identified new driver alterations, discovered a new mutational signature (SBS-RT), recognized an oxidative phosphorylation (OXPHOS)high-B cell receptor (BCR)low-signaling transcriptional axis in RT and showed that OXPHOS inhibition reduces the proliferation of RT cells. These findings demonstrate the early seeding of subclones driving advanced stages of cancer evolution and uncover potential therapeutic targets for RT.

BRCA1 mutations in high-grade serous ovarian cancer are associated with proteomic changes in DNA repair, splicing, transcription regulation and signaling.

Despite recent advances in the management of BRCA1 mutated high-grade serous ovarian cancer (HGSC), the physiology of these tumors remains poorly understood. Here we provide a comprehensive molecular understanding of the signaling processes that drive HGSC pathogenesis with the addition of valuable ubiquitination profiling, and their dependency on BRCA1 mutation-state directly in patient-derived tissues. Using a multilayered proteomic approach, we show the tight coordination between the ubiquitination and phosphorylation regulatory layers and their role in key cellular processes related to BRCA1-dependent HGSC pathogenesis. In addition, we identify key bridging proteins, kinase activity, and post-translational modifications responsible for molding distinct cancer phenotypes, thus providing new opportunities for therapeutic intervention, and ultimately advance towards a more personalized patient care.

BCL2 translocation in high grade B cell lymphoma (NOS, DH/TH) is associated with reduced progression free survival.

High Grade B Cell Lymphoma, NOS, and High Grade B Cell Lymphoma with Dual Hit or Triple Hit have been recently recategorized in the 2016 revision of the WHO classification of lymphoid neoplasms. In this study we have characterized the genetic, histopathological, and clinical features of a series of this type of lymphoid neoplasia (17 HGBCL NOS and 53 HGBCL DH/TH).HGBCL NOS showed better response to first line treatment than HGBCL with DH/TH but no significant differences in PFS or OS were found between the two categories. Survival analysis in the whole cohort of cases found that only the presence of BCL2 translocation was significantly associated with PFS. Other clinical features such as IPI, LDH or stage were equivalent in both categories. Furthermore, both high grade and DLBCL morphological patterns showed equivalent PFS and OS in this set of High grade BCL NOS/DH/TH.Key pointsBCL2 translocation in High Grade B Cell Lymphoma NOS and High Grade B Cell Lymphoma with DH/TH is associated with reduced progression free survival.Both high grade and DLBCL morphological patterns showed equivalent outcome regarding PFS and OS in HGBCL.

Vulvar Adenocarcinoma of Intestinal Type: A Case Report of an Uncommon Entity.

Vulvar cancer is rare and accounts for only 5% of all gynecologic cancers. Squamous cell carcinoma is the most common and makes up 90% of the cases. Vulvar adenocarcinoma usually arises in Bartholin and other vulvar glands. Primary vulvar intestinal-type adenocarcinoma is an extremely rare disease with an unclear prognosis and treatment. Its origin is still unknown, the most accepted theory suggests cloacal remnants as the source of origin. Only a few cases have been reported in the literature. We present a case of a 66-yr-old female who presented with vulvar pruritus and local discomfort, showing a 2 cm tumor located in the left labium minor in the region of vulvar fourchette. Wide vulvar excision and bilateral lymph nodes dissection were performed. Other concomitant lesions and distant extension of tumor were ruled out by positron emission tomography. Pathologic study revealed a colonic-type adenocarcinoma with typical villoglandular architecture with an irregular glandular structure composed of atypical columnar epithelium. The lesion had direct contact with epidermal surface and mainly was external without involving the dermis. Immunohistochemical analysis revealed positive staining for cytokeratin 20 and CDX2. p16 showed an abnormal diffuse and strong immunoexpression. The presence of a low-risk human papillomavirus was detected by polymerase chain reaction, therefore, the expression of p16 cannot be explained in this case by the presence of human papillomavirus. Additional studies are needed in additional cases to clarify the role of human papillomavirus in this kind of tumor.

SDCBP Modulates Stemness and Chemoresistance in Head and Neck Squamous Cell Carcinoma through Src Activation.

To characterize the mechanisms that govern chemoresistance, we performed a comparative proteomic study analyzing head and neck squamous cell carcinoma (HNSCC) cells: CCL-138 (parental), CCL-138-R (cisplatin-resistant), and cancer stem cells (CSCs). Syntenin-1 (SDCBP) was upregulated in CCL-138-R cells and CSCs over parental cells. SDCBP depletion sensitized biopsy-derived and established HNSCC cell lines to cisplatin (CDDP) and reduced CSC markers, Src activation being the main SDCBP downstream target. In mice, SDCBP-depleted cells formed tumors with decreased mitosis, Ki-67 positivity, and metastasis over controls. Moreover, the fusocellular pattern of CCL-138-R cell-derived tumors reverted to a more epithelial morphology upon SDCBP silencing. Importantly, SDCBP expression was associated with Src activation, poor differentiated tumor grade, advanced tumor stage, and shorter survival rates in a series of 382 HNSCC patients. Our results reveal that SDCBP might be a promising therapeutic target for effectively eliminating CSCs and CDDP resistance.

Molecular and functional profiling identifies therapeutically targetable vulnerabilities in plasmablastic lymphoma.

Plasmablastic lymphoma (PBL) represents a rare and aggressive lymphoma subtype frequently associated with immunosuppression. Clinically, patients with PBL are characterized by poor outcome. The current understanding of the molecular pathogenesis is limited. A hallmark of PBL represents its plasmacytic differentiation with loss of B-cell markers and, in 60% of cases, its association with Epstein-Barr virus (EBV). Roughly 50% of PBLs harbor a MYC translocation. Here, we provide a comprehensive integrated genomic analysis using whole exome sequencing (WES) and genome-wide copy number determination in a large cohort of 96 primary PBL samples. We identify alterations activating the RAS-RAF, JAK-STAT, and NOTCH pathways as well as frequent high-level amplifications in MCL1 and IRF4. The functional impact of these alterations is assessed using an unbiased shRNA screen in a PBL model. These analyses identify the IRF4 and JAK-STAT pathways as promising molecular targets to improve outcome of PBL patients.

Cell free circulating tumor DNA in cerebrospinal fluid detects and monitors central nervous system involvement of B-cell lymphomas.

The levels of cell free circulating tumor DNA (ctDNA) in plasma correlated with treatment response and outcome in systemic lymphomas. Notably, in brain tumors, the levels of ctDNA in the cerebrospinal fluid (CSF) are higher than in plasma. Nevertheless, their role in central nervous system (CNS) lymphomas remains elusive. We evaluated the CSF and plasma from 19 patients: 6 restricted CNS lymphomas, 1 systemic and CNS lymphoma, and 12 systemic lymphomas. We performed whole exome sequencing or targeted sequencing to identify somatic mutations of the primary tumor, then variant-specific droplet digital PCR was designed for each mutation. At time of enrolment, we found ctDNA in the CSF of all patients with restricted CNS lymphoma but not in patients with systemic lymphoma without CNS involvement. Conversely, plasma ctDNA was detected in only 2/6 patients with restricted CNS lymphoma with lower variant allele frequencies than CSF ctDNA. Moreover, we detected CSF ctDNA in 1 patient with CNS lymphoma in complete remission and in 1 patient with systemic lymphoma, 3 and 8 months before CNS relapse was confirmed; indicating CSF ctDNA might detect CNS relapse earlier than conventional methods. Finally, in 2 cases with CNS lymphoma, CSF ctDNA was still detected after treatment even though a complete decrease in CSF tumor cells was observed by flow cytometry (FC), indicating CSF ctDNA better detected residual disease than FC. In conclusion, CSF ctDNA can better detect CNS lesions than plasma ctDNA and FC. In addition, CSF ctDNA predicted CNS relapse in CNS and systemic lymphomas.

Clinical and pathological characteristics of peripheral T-cell lymphomas in a Spanish population: a retrospective study.

We investigated the clinicopathological features and prognostic factors of patients with peripheral T-cell lymphoma (PTCL) in 13 sites across Spain. Relevant clinical antecedents, CD30 expression and staining pattern, prognostic indices using the International Prognostic Index and the Intergruppo Italiano Linfomi system, treatments, and clinical outcomes were examined. A sizeable proportion of 175 patients had a history of immune-related disorders (autoimmune 16%, viral infections 17%, chemo/radiotherapy-treated carcinomas 19%). The median progression-free survival (PFS) and overall survival (OS) were 7·9 and 15·8 months, respectively. Prognostic indices influenced PFS and OS, with a higher number of adverse factors resulting in shorter survival (P < 0·001). Complete response (CR) to treatment was associated with better PFS (62·6 vs. 4 months; P < 0·001) and longer OS (67·0 vs. 7·3 months; P < 0·001) compared to no CR. CD30 was expressed across all subtypes; >15% of cells were positive in anaplastic lymphoma kinase-positive and -negative anaplastic large-cell lymphoma and extranodal natural killer PTCL groups. We observed PTCL distribution across subtypes based on haematopathological re-evaluation. Poor prognosis, effect of specific prognostic indices, relevance of histopathological sub-classification, and response level to first-line treatment on outcomes were confirmed. Immune disorders amongst patients require further examination involving genetic studies and identification of associated immunosuppressive factors.

Cytokeratin expression in plasmablastic lymphoma - a possible diagnostic pitfall in the routine work-up of tumours.

AIMS: Plasmablastic lymphoma (PBL) is a rare aggressive B-cell lymphoma that frequently arises at extranodal sites in the setting of immunosuppression. The diagnosis of PBL is complex, owing to a frequent solid or cohesive growth pattern, and an often unusual immunophenotype. Several case reports have described cytokeratin (CK) expression in PBL, introducing a diagnostic pitfall. The aim of this study was to determine the frequency of CK expression in PBL in the largest series available to date. METHODS AND RESULTS: By using immunohistochemistry in a cohort of 72 PBLs, we identified CK8/18 positivity in 11 of 72 cases (15%) and AE1/3 positivity in six of 65 cases (9%), clearly contrasting with a control series of non-PBL aggressive B-cell lymphomas (one of 96 diffuse large B-cell lymphomas), as well as with data in the literature describing only occasional CK expression in haematological neoplasms. CONCLUSIONS: Our data indicate CK expression in a substantial number (15%) of PBLs. In view of the particular morphological features of PBL and its frequent negativity for the common leukocyte antigen and B-cell markers, this feature represents a pitfall in the routine diagnostic work-up of PBL, and requires more extensive immunohistochemical and molecular characterisation of cases entering the differential diagnosis.

Per-operative fluid therapy, vasopressor and transfusion rate in DIEP-flap breast reconstruction. A series of cases / Fluidoterapia, uso de vasopresores y tasa transfusional peroperatoria en la reconstrucción mamaria con colgajo DIEP. Una serie de casos

OBJECTIVE: Anesthetic management in DIEP-flap breast reconstruction surgery may influence the appearance of postoperative complications. Fluid therapy, vasopressor use, and blood management are controversial. The aim was to audit hemodynamic management and to assess its impact on perioperative outcomes. MATERIAL AND METHODS: Sixty-seven cases of DIEP-flap breast reconstruction were reviewed. Data collected: anthropometric data; ASA score; comorbidities; timing of reconstruction (immediate/delayed), type of reconstruction (unilateral/bilateral); length of surgery; per-operative complications; per-operative fluid therapy, use of vasopressors, transfusion rate; re-intervention requirements; surgical success rate; hospital stay, and readmission rate. RESULTS: Median crystalloid infusion rate was 3.18 (2.63-3.76) ml/kg/h in the first 24 hours. Intraoperatively, colloids were administered in 35 (52%) patients at a median infusion rate of 1.40 (1.08-1.86) ml/Kg/h; 21 (60%) of them presented some postoperative complication. Hypotensive events were registered in 13 (19%) patients; 9 (69%) suffered some postoperative complication. The only vasopressor used was Ephedrine in 14 (21%) patients, at a median dose of 0 (0-6) mg. Red blood cell (RBC) transfusion was required in 18 (27%) patients. All of the patients who were transfused, 11 (61%) presented some postoperative complication. Hospital stay was 7 (7-9) days. Surgery was successful in 46 (69%) patients and readmission was necessary in 11 (16%) patients. CONCLUSIONS: Colloids administration, intraoperative hypotensive events, RBC transfusion, and delayed surgery are variables that could increase the risk of postoperative complications in our series.

OBJETIVO: El manejo anestésico en la cirugía de reconstrucción mamaria con colgajo DIEP podría influir en la aparición de complicaciones posoperatorias. La fluidoterapia, el uso de vasopresores y la tasa transfusional son motivo de controversia. Nuestro objetivo fue auditar el manejo hemodinámico y valorar su impacto en los resultados perioperatorios. MATERIAL Y MÉTODOS: Analizamos 67 pacientes programadas para reconstrucción mamaria con colgajo DIEP. Datos registrados: antropométricos; ASA; comorbilidades; momento de la reconstrucción (inmediata/diferida); tipo de reconstrucción (unilateral/bilateral); duración quirúrgica; complicaciones perioperatorias; fluidoterapia, vasopresores y tasa transfusional peroperatorios; tasa de reintervención, reingresos y éxito de la cirugía; estancia hospitalaria. RESULTADOS: La velocidad promedio de infusión de cristaloides fue de 3,18 (2,63-3,76) ml/kg/h en las primeras 24 h. Intraoperatoriamente se administraron coloides en 35 (52%) pacientes a una velocidad promedio de infusión de 1,40 (1,08-1,86) ml/kg/h, presentando complicaciones posoperatorias en 21 (60%) casos. Trece (19%) pacientes presentaron eventos hipotensivos intraoperatorios, registrándose complicaciones en 9 (69%). El único vasopresor utilizado fue la efedrina en 14 (21%) pacientes, a una dosis mediana de 0 (0-6) mg. Requirieron transfusión sanguínea 18 (27%) pacientes. Del total de pacientes transfundidos, 11 (61%) habían presentado alguna complicación posoperatoria. La cirugía fue un éxito en 46 (69%) casos. La estancia hospitalaria fue de 7 (7-9) días y el reingreso fue necesario en 11 (16%) casos. CONCLUSIONES: La administración de coloides, los eventos hipotensivos intraoperatorios, la transfusión de hemoderivados y la cirugía con reconstrucción tardía son variables que podrían incrementar el riesgo de complicaciones posoperatorias.

Five microRNAs in Serum Are Able to Differentiate Breast Cancer Patients From Healthy Individuals.

Breast cancer is the cancer with the most incidence and mortality in women. microRNAs are emerging as novel prognosis/diagnostic tools. Our aim was to identify a serum microRNA signature useful to predict cancer development. We focused on studying the expression levels of 30 microRNAs in the serum of 96 breast cancer patients vs. 92 control individuals. Bioinformatic studies provide a microRNA signature, designated as a predictor, based on the expression levels of five microRNAs. Then, we tested the predictor in a group of 60 randomly chosen women. Lastly, a proteomic study unveiled the overexpression and downregulation of proteins differently expressed in the serum of breast cancer patients vs. that of control individuals. Twenty-six microRNAs differentiate cancer tissue from healthy tissue, and 16 microRNAs differentiate the serum of cancer patients from that of the control group. The tissue expression of miR-99a, miR-497, miR-362, and miR-1274, and the serum levels of miR-141 correlated with patient survival. Moreover, the predictor consisting of miR-125b, miR-29c, miR-16, miR-1260, and miR-451 was able to differentiate breast cancer patients from controls. The predictor was validated in 20 new cases of breast cancer patients and tested in 60 volunteer women, assigning 11 out of 60 women to the cancer group. An association of low levels of miR-16 with a high content of CD44 protein in serum was found. Circulating microRNAs in serum can represent biomarkers for cancer prediction. Their clinical relevance and the potential use of the predictor here described are discussed.

TSPAN1: A Novel Protein Involved in Head and Neck Squamous Cell Carcinoma Chemoresistance.

Sensitization of resistant cells and cancer stem cells (CSCs) represents a major challenge in cancer therapy. A proteomic study revealed tetraspanin-1 (TSPAN1) as a protein involved in acquisition of cisplatin (CDDP) resistance (Data are available via ProteomeXchange with identifier PXD020159). TSPAN1 was found to increase in CDDP-resistant cells, CSCs and biopsies from head and neck squamous cell carcinoma (HNSCC) patients. TSPAN1 depletion in parental and CDDP-resistant HNSCC cells reduced cell proliferation, induced apoptosis, decreased autophagy, sensitized to chemotherapeutic agents and inhibited several signaling cascades, with phospho-SRC inhibition being a major common target. Moreover, TSPAN1 depletion in vivo decreased the size and proliferation of parental and CDDP-resistant tumors and reduced metastatic spreading. Notably, CDDP-resistant tumors showed epithelial-mesenchymal transition (EMT) features that disappeared upon TSPAN1 inhibition, suggesting a link of TSPAN1 with EMT and metastasis. Immunohistochemical analysis of HNSCC specimens further revealed that TSPAN1 expression was correlated with phospho-SRC (pSRC), and inversely with E-cadherin, thus reinforcing TSPAN1 association with EMT. Overall, TSPAN1 emerges as a novel oncogenic protein and a promising target for HNSCC therapy.