Targeted therapies in lung adenocarcinomas: new methodologies and new markers

Il cancro ai polmoni \ue8 la patologia neoplastica con il tasso di mortalit\ue0 pi\uf9 elevato. L\u2019adenocarcinoma (AC), che rappresenta il 60% dei tumori polmonari non a piccole cellule (NSCLC), \ue8 l\u2019istotipo pi\uf9 diffuso e attaualmente viene trattato mediante resezione chirurgica combinata con un regime chemioterapico basato su platino (Pt) abbinato ad una coppia di molecole citotossiche. Con lo scopo di risolvere gli svantaggi del trattamento chemioterapico, negli ultimi anni sono stati sviluppati farmaci a bersaglio molecolare. Le terapie molecolari maggiormente utilizzate per gli AC polmonari sono gli inibitori tirosin-chinasici (TKIs) diretti contro il recettore del fattore di crescita dell\u2019epidermide (EGFR) e contro la chinasi del linfoma anaplastico (ALK). Lo scopo del mio progetto \ue8 stato quello di migliorare la cura dei pazienti affetti da AC polmonare sia tramite l\u2019implementazione dei saggi per analizzare EGFR in campioni tissutali e biopsie liquide sia tramite la valutazione dell\u2019espressione di un nuovo possibile bersaglio di farmaci molecolari: il recettore tirosin-chinasico orfano da ligando-1 (ROR1). I nuovi saggi (SensiScreen\uae) sono stati validati su due coorti retrospettive di pazienti affetti da AC polmonare: la prima rappresentata da 471 campioni di tessuto e la seconda rappresentata da 61 campioni di plasma, 5 di siero e 39 di tessuto dagli stessi pazienti. SensiScreen\uae conferma le mutazioni trovate con DS e con le altre metodologie, ma soprattutto permette di analizzare alcuni casi risultati non valutabili con gli altri saggi e consente di trovare nuovi casi mutati. L\u2019espressione di ROR1 e di miR-382 (un microRNA, miRNA, coinvolto nell\u2019inibizione di ROR1) \ue8 stata valutata con TaqMan real-time PCR in una terza coorte retrospettiva costituita da 102 pazienti affetti da AC polmonare. Le nostre analisi dimostrano un\u2019overespressione di ROR1 e di miR-382 nel 28.6% e nel 48.1% dei casi rispettivamente

P1245 Polymorphic Variants of HSD3B1 Gene Confer Different Outcome in Specific Subgroups of Patients Infected With SARS-CoV-2

Introduction: Severe respiratory syndrome coronavirus 2 (SARS-CoV-2) uses the androgen receptor (AR), through ACE2 receptor and TMPRSS2, to enter nasal and upper airways epithelial cells. Genetic analyses revealed that HSD3B1 P1245C polymorphic variant increases dihydrotestosterone production and upregulation of TMPRSS2 with respect to P1245A variant, thus possibly influencing SARS-CoV-2 infection. Our aim was to characterize the HSD3B1 polymorphism status and its potential association with clinical outcomes in hospitalized patients with COVID-19 in Southern Switzerland. Materials and Methods: The cohort included 400 patients hospitalized for COVID-19 during the first wave between February and May 2020 in two different hospitals of Canton Ticino. Genomic DNA was extracted from formalin-fixed paraffin-embedded tissue blocks, and HSD3B1 gene polymorphism was evaluated by Sanger sequencing. Statistical associations were verified using different test. Results: HSD3B1 polymorphic variants were not associated with a single classical factor related to worse clinical prognosis in hospitalized patients with SARS-CoV-2. However, in specific subgroups, HSD3B1 variants played a clinical role: intensive care unit admission was more probable in patients with P1245C diabetes compared with P1245A individuals without this comorbidity and death was more associated with hypertensive P1245A>C cases than patients with P1245A diabetes without hypertension. Discussion: This is the first study showing that HSD3B1 gene status may influence the severity of SARS-CoV-2 infection. If confirmed, our results could lead to the introduction of HSD3B1 gene status analysis in patients infected with SARS-CoV-2 to predict clinical outcome. Keywords: HSD3B1 gene polymorphism; Likelihood-ratio tests; SARS-CoV-2; androgen receptor; direct sequencing

Recent and Future Strategies to Overcome Resistance to Targeted Therapies and Immunotherapies in Metastatic Colorectal Cancer

Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide, and 20% of patients with CRC present at diagnosis with metastases. The treatment of metastatic CRC is based on a fluoropyrimidine-based chemotherapy plus additional agents such as oxaliplatin and irinotecan. To date, on the basis of the molecular background, targeted therapies (e.g., monoclonal antibodies against epidermal growth factor receptor or inhibiting angiogenesis) are administered to improve the treatment of metastatic CRC. In addition, more recently, immunological agents emerged as effective in patients with a defective mismatch repair system. The administration of targeted therapies and immunotherapy lead to a significant increase in the survival of patients; however these drugs do not always prove effective. In most cases the lack of effectiveness is due to the development of primary resistance, either a resistance-inducing factor is already present before treatment or resistance is acquired when it occurs after treatment initiation. In this review we describe the most relevant targeted therapies and immunotherapies and expand on the reasons for resistance to the different approved or under development targeted drugs. Then we showed the possible mechanisms and drugs that may lead to overcoming the primary or acquired resistance in metastatic CRC

Research progress on KRAS mutations in colorectal cancer

The RAS gene family, responsible for signal transduction within the mitogen activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PI3K) pathways, is frequently involved in carcinogenesis, and alterations in its member genes can be detected, with variable frequency, in a wide variety of solid and hematological cancers. These alterations may behave as prognostic-predictive biomarkers and driver mutations, making them an interesting therapeutic target. Since their discovery, many strategies have been pursued to act on their signaling pathways. Indeed, in clinical practice, KRAS, the most prominent member of the RAS gene family, represents an especially elusive target in most malignancies; pathway inhibition is carried out upstream, on the EGFR receptor, or downstream, most frequently on the BRAF/MEK/ERK cascade. Recently, clinically relevant direct RAS inhibition has been successfully achieved with the development of potent and selective covalent inhibitors of KRAS c.34G>T (p.G12C). These latest-generation drugs represent both a new and interesting tool in the therapeutic armamentarium and a symbolic end to the myth of KRAS undruggability. However, their clinical relevance and appropriate place in treatment strategies remain to be determined

Role of NEU3 Overexpression in the Prediction of Efficacy of EGFR-Targeted Therapies in Colon Cancer Cell Lines

The epidermal growth factor receptor (EGFR), through the MAP kinase and PI3K-Akt-mTOR axis, plays a pivotal role in colorectal cancer (CRC) pathogenesis. The membrane-associated NEU3 sialidase interacts with and desialylates EGFR by promoting its dimerization and downstream effectors’ activation. Among the targeted therapies against EGFR, the monoclonal antibody cetuximab is active only in a subgroup of patients not carrying mutations in the MAP kinase pathway. In order to better understand the EGFR-NEU3 interplay and the mechanisms of pharmacological resistance, we investigated the role of NEU3 deregulation in cetuximab-treated CRC cell lines transiently transfected with NEU3 using Western blot analysis. Our results indicate that NEU3 overexpression can enhance EGFR activation only if EGFR is overexpressed, indicating the existence of a threshold for NEU3-mediated EGFR activation. This enhancement mainly leads to the constitutive activation of the MAP kinase pathway. Consequently, we suggest that the evaluation of NEU3 expression cannot entirely substitute the evaluation of EGFR because EGFR-negative cases cannot be stimulated by NEU3. Furthermore, NEU3-mediated hyperactivation of EGFR is counterbalanced by the administration of cetuximab, hypothesizing that a combined treatment of NEU3- and EGFR-targeted therapies may represent a valid option for CRC patients, which must be investigated in the future

Molecular Biology and Therapeutic Perspectives for K-Ras Mutant Non-Small Cell Lung Cancers

In non-small cell lung cancer (NSCLC) the most common alterations are identified in the Kirsten rat sarcoma viral oncogene homolog (KRAS) gene, accounting for approximately 30% of cases in Caucasian patients. The majority of mutations are located in exon 2, with the c.34G > T (p.G12C) change being the most prevalent. The clinical relevance of KRAS mutations in NSCLC was not recognized until a few years ago. What is now emerging is a dual key role played by KRAS mutations in the management of NSCLC patients. First, recent data report that KRAS-mutant lung AC patients generally have poorer overall survival (OS). Second, a KRAS inhibitor specifically targeting the c.34G > T (p.G12C) variant, Sotorasib, has been approved by the U.S. Food and Drug Administration (FDA) and by the European Medicines Agency. Another KRAS inhibitor targeting c.34G > T (p.G12C), Adagrasib, is currently being reviewed by the FDA for accelerated approval. From the description of the biology of KRAS-mutant NSCLC, the present review will focus on the clinical aspects of KRAS mutations in NSCLC, in particular on the emerging efficacy data of Sotorasib and other KRAS inhibitors, including mechanisms of resistance. Finally, the interaction between KRAS mutations and immune checkpoint inhibitors will be discussed

Non-small cell lung cancer (NSCLC), EGFR downstream pathway activation and TKI targeted therapies sensitivity: Effect of the plasma membrane-associated NEU3

Adenocarcinoma of Non-Small Cell Lung Cancer (NSCLC) is a severe disease. Patients carrying EGFR mutations may benefit from EGFR targeted therapies (e.g.: gefitinib). Recently, it has been shown that sialidase NEU3 directly interacts and regulates EGFR. In this work, we investigate the effect of sialidase NEU3 overexpression on EGFR pathways activation and EGFR targeted therapies sensitivity, in a series of lung cancer cell lines. NEU3 overexpression, forced after transfection, does not affect NSCLC cell viability. We demonstrate that NEU3 overexpression stimulates the ERK pathway but this activation is completely abolished by gefitinib treatment. The Akt pathway is also hyper-activated upon NEU3 overexpression, but gefitinib is able only to decrease, and not to abolish, such activa- tion. These findings indicate that NEU3 can act directly on the ERK pathway through EGFR and both directly and indirectly with respect to EGFR on the Akt pathway. Furthermore, we provide evidence that a healthy mucosa cell line (with EGFR wild-type gene sequence) is slightly sensitive to gefitinib, especially in the presence of NEU3 overexpression, thus hypothesizing that NEU3 overexpressing patients may benefit from EGFR targeted thera- pies also in absence of EGFR point mutations. Overall, the expression of NEU3 may be a novel diagnostic marker in NSCLC because, by its ability to stimulate EGFR downstream pathways with direct and indirect mechanisms, it may help in the identification of patients who can profit from EGFR targeted therapies in absence of EGFR activating mutations or from new combinations of EGFR and Akt inhibitors

Definition of MYC genetic heteroclonality in diffuse large B-cell lymphoma with 8q24 rearrangement and its impact on protein expression

MYC rearrangement can be detected in a subgroup of diffuse large B-cell lymphoma characterized by unfavorable prognosis. In contrast to Burkitt lymphoma, the correlation between MYC rearrangement and MYC protein expression in diffuse large B-cell lymphoma is less clear, as approximately one-third of rearranged cases show negative or low expression by immunohistochemistry. To better understand whether specific characteristics of the MYC rearrangement may influence its protein expression, we investigated 43 de novo diffuse large B-cell lymphoma positive for 8q24 rearrangement by FISH, using 14 Burkitt lymphoma for comparison. Different cell populations (clones), breakpoints (classical vs non-classical FISH patterns), partner genes (IGH vs non-IGH) and immunostaining were detected and analyzed using computerized image systems. In a subgroup of diffuse large B-cell lymphoma, we observed different clones within the same tumor distinguishing the founder clone with MYC rearrangement alone from other subclones, carrying MYC rearrangement coupled with loss/extra copies of derivatives/normal alleles. This picture, which we defined MYC genetic heteroclonality, was found in 42% of cases and correlated to negative MYC expression (P=0.026). Non-classical FISH breakpoints were detected in 16% of diffuse large B-cell lymphoma without affecting expression (P=0.040). Non-IGH gene was the preferential partner of rearrangement in those diffuse large B-cell lymphoma showing MYC heteroclonality (P=0.016) and/or non-classical FISH breakpoints (P=0.058). MYC heteroclonality was not observed in Burkitt lymphoma and all cases had positive MYC expression. Non-classical FISH MYC breakpoint and non-IGH partner were found in 29 and 20% of Burkitt lymphoma, respectively. In conclusion, MYC genetic heteroclonality is a frequent event in diffuse large B-cell lymphoma and may have a relevant role in modulating MYC expression.Modern Pathology advance online publication, 29 April 2016; doi:10.1038/modpathol.2016.71

Deregulation of sialidases in human normal and tumor tissues

BACKGROUND: Aberrant sialylation is a characteristic feature associated with cancer. The four types of mammalian sialidases identified to date have been shown to behave in different manners during carcinogenesis. While NEU1, NEU2 and NEU4 have been observed to oppose malignant phenotypes, the membrane-bound sialidase NEU3 was revealed to promote cancer progression. OBJECTIVES: With the aim of improving the knowledge about sialidases deregulation in various cancer types, we investigated the amount of NEU1, NEU3 and NEU4 transcripts in paired normal and tumor tissues from 170 patients with 11 cancer types. METHODS: mRNA was extracted from patients tissue specimens and retrotranscribed into cDNA, which was quantified by Real-Time PCR. RESULTS: We found NEU1 and NEU3 to be up regulated, while NEU4 was down regulated in most cancer types. In particular, colorectal cancer tissues showed the highest increase in NEU3 expression. Both NEU1 and NEU3 showed a strong up-regulation in ovarian cancer. CONCLUSIONS: Our data show that human sialidases are expressed at different levels in healthy tissues and are strongly deregulated in tumors. Moreover, sialidases expression in our European cohort showed significant differences from Asian populations. Some of these peculiar features open up potential applications of sialidases in cancer diagnosis and therapy

Akt phosphorylation levels after EGF stimulation, sialidase NEU3 overexpression and gefitinib treatment.

<p>(A) Representative Western-blot analyses performed on normal lung cell line (HSAEC1) and NSCLC cell lines (HCC4006 and H1734) transfected with either the empty vector (mock) or pcDNA3.1-HsNEU3. Cells were treated for 3 h with 1 μM gefitinib, followed by the addition of EGF (20 ng/mL) for 15 min. Protein extracts were separated on a 10% SDS-PAGE and probed with anti-Akt, anti-P-Akt antibodies. Vinculin was used as a loading control. The experiments were performed in triplicate. (B)–(C)–(D) Densitometric analysis was performed with Scion Image Software. Values are expressed by comparing the data obtained after EGF stimulation with those obtained without EGF (B); by comparing the data obtained after transfection with NEU3 with those obtained after transfection with the empty vector (mock) (C); by comparing the data obtained after gefitinib treatment with those obtained without gefitinib administration (D). Statistical analyses were performed using Student’s t-test. Values are presented as means ± standard error (SE). *p<0.05, **p<0.01, and ***p<0.001 (Student’s t-test).</p