Beyond Traditional Morphological Characterization of Lung Neuroendocrine Neoplasms: In Silico Study of Next-Generation Sequencing Mutations Analysis across the Four World Health Organization Defined Groups

Lung neuroendocrine neoplasms (LNENs) classes, as proposed by the World Health Organization 2015, do not provide properly prognostic and therapeutic indications. In fact, high-throughput molecular analysis, based on next-generation sequencing, identified novel molecular subgroups, associated with different genomic signatures, that could pave the way for alternative therapeutic approaches. The present review, coupled with in silico molecular analysis, could show the current genomic alterations state in actual LNENS groups. Interestingly our manuscript suggests that the molecular novelties could improve the LNENs therapeutics efficacy. In more detail, we reported the differences of gene alterations and mutational rate between LNENS, confirming the central pathogenetic role given by a different mutational rate in chromatin remodeling genes and tumor suppressors TP53-RB1. In conclusion, our results underlined that a further molecular layer is needed to improve the efficacy of LNENs medical treatment.Lung neuroendocrine neoplasms (LNENs) represent a rare and heterogeneous population of lung tumors. LNENs incidence rate has increased dramatically over the past 30 years. The current World Health Organization LNENs classification (WHO 2015), distinguished four LNENs prognostic categories, according to their morphology, necrosis amount and mitotic count: typical carcinoid (TC), atypical-carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung cancer (SCLC). At present, due to their rarity and biological heterogeneity there is still no consensus on the best therapeutic approach. Next-generation-sequencing analysis showed that WHO 2015 LNENs classes, could be characterized also by specific molecular alterations: frequently mutated genes involving chromatin remodeling and generally characterized by low mutational burden (MB) are frequently detected in both TC and AC; otherwise, TP53 and RB1 tumor suppressor genes alterations and high MB are usually detected in LCNEC and SCLC. We provide an overview concerning gene mutations in each WHO 2015 LNENs class in order to report the current LNENs mutational status as potential tool to better understand their clinical outcome and to drive medical treatment

Improved Prognostic Prediction in Never-Smoker Lung Cancer Patients by Integration of a Systemic Inflammation Marker with Tumor Immune Contexture Analysis

Almost 25% of lung cancers (LCs) occur in never-smokers. LC inflammatory profile, based on plasma C-reactive protein levels (CRP), predicts mortality, independently by smoking-status. We hypothesized that: CRP could be associated with tumor immune contexture (TIC) in never-smokers and both these two parameters may improve their prognosis. Sixty-eight never-smokers LC patients with high or low CRP were selected. The programmed cell death protein 1 (PD-1) and its ligand (PD-L1), the human leukocyte antigens (HLA-DR and HLA-I), CD8, CD4, CD3, CD33, CD163, and CD68 were evaluated by immunohistochemistry on surgical samples given TIC evaluation. The classification model based on TIC scores was generated by Classification and Regression Tree analysis. Tumor mutational burden was evaluated by targeted next-generation sequencing. Exclusively high CRP (H-CRP) subset showed PD-L1 expression in 35% of LC as well as lower HLA-I and HLA-DR in their stromal cells. CD3, CD4, CD8, HLA-I, HLA-DR tumor cells staining were associated with a "low inflammatory profile" subset. CRP and LC immune profiles drive clinical outcome: 5-year survival 88% against 8% was associated with low and high-risk profiles (p< 0.0001). Clinical outcome prediction in never-smoker LC patients may be improved by both CRP and tumor immune contexture evaluation

LKB1 Down-Modulation by miR-17 Identifies Patients With NSCLC Having Worse Prognosis Eligible for Energy-Stress–Based Treatments

Abstract Introduction Preclinical models recently unveiled the vulnerability of LKB1/KRAS comutated NSCLC to metabolic stress-based treatments. Because miR-17 is a potential epigenetic regulator of LKB1, we hypothesized that wild-type LKB1 (LKB1WT) NSCLC with high miR-17 expression may be sensitive to an energetic stress condition, and eligible for metabolic frailties-based therapeutic intervention. Methods We took advantage of NSCLC cell lines with different combinations of KRAS mutation and LKB1 deletion and of patient-derived xenografts (PDXs) with high (LKB1WT/miR-17 high) or low (LKB1WT/miR-17 low) miR-17 expression. We evaluated LKB1 pathway impairment and apoptotic response to metformin. We retrospectively evaluated LKB1 and miR-17 expression levels in tissue specimens of patients with NSCLC and PDXs. In addition, a lung cancer series from The Cancer Genome Atlas data set was analyzed for miR-17 expression and potential correlation with clinical features. Results We identified miR-17 as an epigenetic regulator of LKB1 in NSCLC and confirmed targeting of miR-17 to LKB1 3′ untranslated region by luciferase reporter assay. We found that miR-17 overexpression functionally impairs the LKB1/AMPK pathway. Metformin treatment prompted apoptosis on miR-17 overexpression only in LKB1WT cell lines, and in LKB1WT/miR-17 high PDXs. A retrospective analysis in patients with NSCLC revealed an inverse correlation between miR-17 and LKB1 expression and highlighted a prognostic role of miR-17 expression in LKB1WT patients, which was further confirmed by The Cancer Genome Atlas data analysis. Conclusions We identified miR-17 as a mediator of LKB1 expression in NSCLC tumors. This study proposes a miR-17 expression score potentially exploitable to discriminate LKB1WT patients with NSCLC with impaired LKB1 expression and poor outcome, eligible for energy-stress-based treatments

Metformin Enhances Cisplatin-Induced Apoptosis and Prevents Resistance to Cisplatin in Co-mutated KRAS/LKB1 NSCLC

Abstract Introduction We hypothesized that activating KRAS mutations and inactivation of the liver kinase B1 (LKB1) oncosuppressor can cooperate to sustain NSCLC aggressiveness. We also hypothesized that the growth advantage of KRAS/LKB1 co-mutated tumors could be balanced by higher sensitivity to metabolic stress conditions, such as metformin treatment, thus revealing new strategies to target this aggressive NSCLC subtype. Methods We retrospectively determined the frequency and prognostic value of KRAS/LKB1 co-mutations in tissue specimens from NSCLC patients enrolled in the TAILOR trial. We generated stable LKB1 knockdown and LKB1-overexpressing isogenic H1299 and A549 cell variants, respectively, to test the in vitro efficacy of metformin. We also investigated the effect of metformin on cisplatin-resistant CD133+ cells in NSCLC patient-derived xenografts. Results We found a trend towards worse overall survival in patients with KRAS/LKB1 co-mutated tumors as compared to KRAS-mutated ones (hazard ratio: 2.02, 95% confidence interval: 0.94–4.35, p = 0.072). In preclinical experiments, metformin produced pro-apoptotic effects and enhanced cisplatin anticancer activity specifically in KRAS/LKB1 co-mutated patient-derived xenografts. Moreover, metformin prevented the development of acquired tumor resistance to 5 consecutive cycles of cisplatin treatment (75% response rate with metformin-cisplatin as compared to 0% response rate with cisplatin), while reducing CD133+ cells. Conclusions LKB1 mutations, especially when combined with KRAS mutations, may define a specific and more aggressive NSCLC subtype. Metformin synergizes with cisplatin against KRAS/LKB1 co-mutated tumors, and may prevent or delay the onset of resistance to cisplatin by targeting CD133+ cancer stem cells. This study lays the foundations for combining metformin with standard platinum-based chemotherapy in the treatment of KRAS/LKB1 co-mutated NSCLC

Genomic and transcriptomic analyses of thyroid cancers identify DICER1 somatic mutations in adult follicular-patterned RAS-like tumors

BackgroundPapillary thyroid carcinoma (PTC) is the most common type of thyroid cancer (TC). Several genomic and transcriptomic studies explored the molecular landscape of follicular cell-derived TCs, and BRAFV600E, RAS mutations, and gene fusions are well-established drivers. DICER1 mutations were described in specific sets of TC patients but represent a rare event in adult TC patients.MethodsHere, we report the molecular characterization of 30 retrospective follicular cell-derived thyroid tumors, comprising PTCs (90%) and poorly differentiated TCs (10%), collected at our Institute. We performed DNA whole-exome sequencing using patient-matched control for somatic mutation calling, and targeted RNA-seq for gene fusion detection. Transcriptional profiles established in the same cohort by microarray were investigated using three signaling-related gene signatures derived from The Cancer Genome Atlas (TCGA).ResultsThe occurrence of BRAFV600E (44%), RAS mutations (13%), and gene fusions (13%) was confirmed in our cohort. In addition, in two patients lacking known drivers, mutations of the DICER1 gene (p.D1709N and p.D1810V) were identified. DICER1 mutations occur in two adult patients with follicular-pattern lesions, and in one of them a second concurrent DICER1 mutation (p.R459*) is also observed. Additional putative drivers include ROS1 gene (p.P2130A mutation), identified in a patient with a rare solid-trabecular subtype of PTC. Transcriptomics indicates that DICER1 tumors are RAS-like, whereas the ROS1-mutated tumor displays a borderline RAS-/BRAF-like subtype. We also provide an overview of DICER1 and ROS1 mutations in thyroid lesions by investigating the COSMIC database.ConclusionEven though small, our series recapitulates the genetic background of PTC. Furthermore, we identified DICER1 mutations, one of which is previously unreported in thyroid lesions. For these less common alterations and for patients with unknown drivers, we provide signaling information applying TCGA-derived classification

Different clinical effects upon separate inhibition of coexisting EGFR and PI3KCA mutations in a lung adenocarcinoma patient

We present a very interesting case of lung adenocarcinoma carrying an uncommon EGFR exon 19 insertion with concomitant PIK3CA mutation showing dramatic and persisting improvement upon erlotinib therapy, after progression during PI3K inhibitor

Prevalence of BRCA homopolymeric indels in an ION Torrent-based tumour-to-germline testing workflow in high-grade ovarian carcinoma

Abstract Tumour DNA sequencing is essential for precision medicine since it guides therapeutic decisions but also fosters the identification of patients who may benefit from germline testing. Notwithstanding, the tumour-to-germline testing workflow presents a few caveats. The low sensitivity for indels at loci with sequences of identical bases (homopolymers) of ion semiconductor-based sequencing techniques represents a well-known limitation, but the prevalence of indels overlooked by these techniques in high-risk populations has not been investigated. In our study, we addressed this issue at the homopolymeric regions of BRCA1/2 in a retrospectively selected cohort of 157 patients affected with high-grade ovarian cancer and negative at tumour testing by ION Torrent sequencing. Variant allele frequency (VAF) of indels at each of the 29 investigated homopolymers was systematically revised with the IGV software. Thresholds to discriminate putative germline variants were defined by scaling the VAF to a normal distribution and calculating the outliers that exceeded the mean + 3 median-adjusted deviations of a control population. Sanger sequencing of the outliers confirmed the occurrence of only one of the five putative indels in both tumour and blood from a patient with a family history of breast cancer. Our results indicated that the prevalence of homopolymeric indels overlooked by ion semiconductor techniques is seemingly low. A careful evaluation of clinical and family history data would further help minimise this technique-bound limitation, highlighting cases in which a deeper look at these regions would be recommended

Molecular Signatures for Combined Targeted Treatments in Diffuse Malignant Peritoneal Mesothelioma

Background—There are currently no effective therapies for diffuse malignant peritoneal mesothelioma (DMPM) patients with disease recurrence. In this study, we investigated the biology of DMPM by analyzing the EGFR family, Axl, and MET, in order to assess the presence of cross-talk between these receptors, suggesting the effectiveness of combined targeted treatments in DMPM. Method—We analyzed a series of 22 naïve epithelioid DMPM samples from a single institute, two of which showed higher-grade malignancy (“progressed”). EGFR, HER2, HER3, Axl, and MET activation and expression were investigated by biochemical analysis, real-time PCR immunofluorescence, immunohistochemistry, next-generation sequencing, miRNA, and mRNA in situ hybridization. Results—In most DMPMs, a strong EGFR activation was associated with HER2, HER3, Axl, and MET co-activation, mediated mainly by receptor heterodimerization and autocrine-paracrine loops induced by the expression of their cognate ligands. Axl expression was downregulated by miRNA34a. Mutations in MET Sema domain were exclusively found in two “progressed” DMPMs, and the combined Axl and MET inhibition reduced cellular motility in a DMPM cell line obtained from a “progressed” DMPM. Conclusion—The results indicate that the coordinated activity of multiple cross-talks between RTKs is directly involved in the biology of DMPM, suggesting the combined inhibition of PIK3 and mTOR as an effective strategy that may be easily implemented in clinical practice, and indicating that the combined inhibition of EGFR/HER2 and HER3 and of Axl and MET deserves further investigation

Molecular Tumor Board as a Clinical Tool for Converting Molecular Data Into Real-World Patient Care

PURPOSE The investigation of multiple molecular targets with next-generation sequencing (NGS) has entered clinical practice in oncology, yielding to a paradigm shift from the histology-centric approach to the mutational model for personalized treatment. Accordingly, most of the drugs recently approved in oncology are coupled to specific biomarkers. One potential tool for implementing the mutational model of precision oncology in daily practice is represented by the Molecular Tumor Board (MTB), a multidisciplinary team whereby molecular pathologists, biologists, bioinformaticians, geneticists, medical oncologists, and pharmacists cooperate to generate, interpret, and match molecular data with personalized treatments. PATIENTS AND METHODS Since May 2020, the institutional MTB set at Fondazione IRCCS Istituto Nazionale Tumori of Milan met weekly via teleconference to discuss molecular data and potential therapeutic options for patients with advanced/metastatic solid tumors. RESULTS Up to October 2021, among 1,996 patients evaluated, we identified >10,000 variants, 43.2% of which were functionally relevant (pathogenic or likely pathogenic). On the basis of functionally relevant variants, 711 patients (35.6%) were potentially eligible to targeted therapy according to European Society of Medical Oncology Scale for Clinical Actionability of Molecular Targets tiers, and 9.4% received a personalized treatment. Overall, larger NGS panels (containing >50 genes) significantly outperformed small panels (up to 50 genes) in detecting actionable gene targets across different tumor types. CONCLUSION Our real-world data provide evidence that MTB is a valuable tool for matching NGS data with targeted treatments, eventually implementing precision oncology in clinical practice

Multistep tumor genetic evolution and changes in immunogenicity trigger immune-mediated disease eradication in stage IV melanoma: lessons from a single case

Durable remissions are observed in 10%–20% of treated patients with advanced metastatic melanoma but the factors associated with long-term complete clinical responses are largely unknown. Here, we report the molecular characteristics of tumor evolution during disease progression along a 9-year clinical course in a patient with advanced disseminated melanoma who received different treatments, including trametinib, ipilimumab, radiation, vemurafenib, surgical tumor debulking and a second ipilimumab course, ultimately achieving complete long-term disease remission.Longitudinal analyses of therapies-resistant metastatic tumors revealed the effects of different treatments on tumor’s microenvironment and immunogenicity, ultimately creating a milieu favorable to immunotherapy response. Monitoring of the temporal dynamics of T cells by analysis of the T cell receptor (TCR) repertoire in the tumor and peripheral blood during disease evolution indicated that T-cell clones with common TCR rearrangements, present at low levels at baseline, were maintained and expanded after immunotherapy, and that TCR diversity increased. Analysis of genetic, molecular, and cellular components of the tumor depicted a multistep process in which treatment with kinase inhibitors strongly conditioned the immune microenvironment creating an inflamed milieu converting cold into hot tumors, while ipilimumab impacted and increased the TCR repertoire, a requirement for tumor rejection.Since the optimal sequencing of treatment with antibodies targeting immune checkpoints and kinase inhibitors for advanced melanoma is still clinically debated, this case indicates that immunotherapy success is possible even after progression on targeted therapy