Impact of ABC transporters in osteosarcoma and ewing’s sarcoma: Which are involved in chemoresistance and which are not?

The ATP-binding cassette (ABC) transporter superfamily consists of several proteins with a wide repertoire of functions. Under physiological conditions, ABC transporters are involved in cellular trafficking of hormones, lipids, ions, xenobiotics, and several other molecules, including a broad spectrum of chemical substrates and chemotherapeutic drugs. In cancers, ABC transporters have been intensely studied over the past decades, mostly for their involvement in the multidrug resistance (MDR) phenotype. This review provides an overview of ABC transporters, both related and unrelated to MDR, which have been studied in osteosarcoma and Ewing’s sarcoma. Since different backbone drugs used in first-line or rescue chemotherapy for these two rare bone sarcomas are substrates of ABC transporters, this review particularly focused on studies that have provided findings that have been either translated to clinical practice or have indicated new candidate therapeutic targets; however, findings obtained from ABC transporters that were not directly involved in drug resistance were also discussed, in order to provide a more complete overview of the biological impacts of these molecules in osteosarcoma and Ewing’s sarcoma. Finally, therapeutic strategies and agents aimed to circumvent ABC-mediated chemoresistance were discussed to provide future perspectives about possible treatment improvements of these neoplasms

Targeting GSTP1-1 induces JNK activation and leads to apoptosis in cisplatin-sensitive and -resistant human osteosarcoma cell lines

The effect of the glutathione transferase P1-1 (GSTP1-1) targeting has been investigated in both sensitive (U-2OS) and cisplatin-resistant (U-2OS/CDDP4μg) human osteosarcoma cell lines. Despite the different enzyme’s content, inhibition of GSTP1-1 by 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) causes the activation of c-Jun N-terminal kinase (JNK) and apoptosis in both cell lines. However, different time courses of JNK activation and cell responses are observed. Whereas in the U-2OS/CDDP4μg cell line drug treatment results in an early increase of caspase activity and secondary necrosis, in the U-2OS cells it mainly causes cell cycle arrest followed by apoptosis. Thereafter, we detailed the action mechanism of NBDHEX in the U-2OS cell line. We report evidence of the interaction between GSTP1-1 and the TNF receptor associated factor 2 (TRAF2) and we demonstrate that NBDHEX is able to dissociate the GSTP1-1:TRAF2 complex. This restores the TRAF2:ASK1 signaling, thereby leading to the simultaneous and prolonged activation of JNK and p38. These mitogen-activated protein kinases (MAPKs) mediate different effects: JNK is crucial for apoptosis, whereas p38 causes an increase in the p21 level and a concomitant cell cycle arrest. Our study shows that GSTP1-1 plays an important regulatory role in TRAF signaling of osteosarcoma and discloses new features of the action mechanism of NBDHEX that suggest potentially practical consequences of these finding

liquid biopsy as tool to monitor and predict clinical benefit from chemotherapy ct and immunotherapy it in advanced non small cell lung cancer ansclc a prospective study

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SMO mutations confer poor prognosis in malignant pleural mesothelioma

Background: Malignant pleural mesothelioma (MPM) is an aggressive tumor but approximately 12% of patients survive more than 3 years. The biological differences underlying better outcomes are not known. Several targeted agents and immunotherapy have been ineffective. Hedgehog (Hh) is one emerging pathway. We compared the biological profiles of patients with different survival, investigating the most frequently altered genes, including the Hh pathway. Methods: We analyzed 56 MPM. A 36-month overall survival (OS) cut-off divided patients into 32 normo (NS) and 24 long (LS) survivors. We used next generation sequencing to test 21 genes, immunohistochemistry to evaluate SMO expression. Mutation differences between NS and LS and their associations with clinical features were analysed by Fisher's test, OS with the Kaplan-Meier method and its association with mutations by univariate and multivariate Cox proportional hazard models. Results: Clinical features were similar in both groups. Eighteen out of 56 patients (32%) were wild-type for the genes analysed. At least five had mutations in BAP1, NF2, TP53, SMO and PTCH1 with no significant differences between the groups except for SMO. SMO, a member of the Hh pathway, was mutated only in NS (15.6%) and only SMO mutations were significantly associated with poor prognosis at univariate (HR =4.36, 95% CI: 2.32-8.18, P<0.0001) and multivariate (HR =9.2, 95% CI: 3.0-28.4, P=0.0001) analysis. All SMO mutated patients expressed high protein levels. Conclusions: SMO mutations were clearly associated with worse prognosis. SMO may be a therapeutic target but this needs to be confirmed in a prospective trial

Real-world data on treatment outcomes in EGFR-mutant non-small-cell lung cancer patients receiving osimertinib in second or further lines

Aims: This study describes real-world outcomes of pretreated EGFR T790M-positive (T790M+) advanced non-small-cell lung cancer patients progressing after first- or second-generation tyrosine kinase inhibitors and receiving osimertinib, compared with T790M-negative (T790M-) patients. We have also described progression patterns and treatment sequences. Patients & methods: This is a retrospective multicenter Italian observational study including consecutive Caucasian patients referred between 2014 and 2018. Results: 167 patients were included. Median progression-free survival was 9.8 months (95% CI: 8.3-13.3) for T790M+ and 6.0 months (95% CI: 4.9-7.2) for T790M- patients, respectively. Median overall survival was 20.7 months (95% CI: 18.9-28.4) for T790M+ and 10.6 months (95% CI: 8.6-23.6) for T790M- patients, respectively. The T790M mutation correlated with absence of new sites of disease. After progression, most T790M+ patients continued osimertinib, whereas most T790M- patients received a different treatment line. Conclusion: Better outcomes were shown in patients receiving osimertinib. A more limited progression pattern for T790M+ was suggested

A multi-center, real-life experience on liquid biopsy practice for EGFR testing in non-small cell lung cancer (NSCLC) patients

Background: circulating tumor DNA (ctDNA) is a source of tumor genetic material for EGFR testing in NSCLC. Real-word data about liquid biopsy (LB) clinical practice are lacking. The aim of the study was to describe the LB practice for EGFR detection in North Eastern Italy. Methods: we conducted a multi-regional survey on ctDNA testing practices in lung cancer patients. Results: Median time from blood collection to plasma separation was 50 min (20\u2013120 min), median time from plasma extraction to ctDNA analysis was 24 h (30 min\u20135 days) and median turnaround time was 24 h (6 h\u20135 days). Four hundred and seventy five patients and 654 samples were tested. One hundred and ninety-two patients were tested at diagnosis, with 16% EGFR mutation rate. Among the 283 patients tested at disease progression, 35% were T790M+. Main differences in LB results between 2017 and 2018 were the number of LBs performed for each patient at disease progression (2.88 vs. 1.2, respectively) and the percentage of T790M+ patients (61% vs. 26%)

Chemotherapy-resistant osteosarcoma is highly susceptible to IL-15-activated allogeneic and autologous NK cells

High-grade osteosarcoma occurs predominantly in adolescents and young adults and has an overall survival rate of about 60%, despite chemotherapy and surgery. Therefore, novel treatment modalities are needed to prevent or treat recurrent disease. Natural killer (NK) cells are lymphocytes with cytotoxic activity toward virus-infected or malignant cells. We explored the feasibility of autologous and allogeneic NK cell–mediated therapies for chemotherapy-resistant and chemotherapy-sensitive high-grade osteosarcoma. The expression by osteosarcoma cells of ligands for activating NK cell receptors was studied in vitro and in vivo, and their contribution to NK cell–mediated cytolysis was studied by specific antibody blockade. Chromium release cytotoxicity assays revealed chemotherapy-sensitive and chemotherapy-resistant osteosarcoma cell lines and osteosarcoma primary cultures to be sensitive to NK cell–mediated cytolysis. Cytolytic activity was strongly enhanced by IL-15 activation and was dependent on DNAM-1 and NKG2D pathways. Autologous and allogeneic activated NK cells lysed osteosarcoma primary cultures equally well. Osteosarcoma patient–derived NK cells were functionally and phenotypically unimpaired. In conclusion, osteosarcoma cells, including chemoresistant variants, are highly susceptible to lysis by IL-15-induced NK cells from both allogeneic and autologous origin. Our data support the exploitation of NK cells or NK cell–activating agents in patients with high-grade osteosarcoma

Evaluation of COVID-19 impact on DELAYing diagnostic-therapeutic pathways of lung cancer patients in Italy (COVID-DELAY study): fewer cases and higher stages from a real-world scenario

Introduction: COVID-19 has disrupted the global health care system since March 2020. Lung cancer (LC) patients (pts) represent a vulnerable population highly affected by the pandemic. This multicenter Italian study aimed to evaluate whether the COVID-19 outbreak had an impact on access to cancer diagnosis and treatment of LC pts compared with pre-pandemic time. Methods: Consecutive newly diagnosed LC pts referred to 25 Italian Oncology Departments between March and December 2020 were included. Access rate and temporal intervals between date of symptoms onset and diagnostic and therapeutic services were compared with the same period in 2019. Differences between the 2 years were analyzed using the chi-square test for categorical variables and the Mann\u2013Whitney U test for continuous variables. Results: A slight reduction ( 126.9%) in newly diagnosed LC cases was observed in 2020 compared with 2019 (1523 versus 1637, P = 0.09). Newly diagnosed LC pts in 2020 were more likely to be diagnosed with stage IV disease (P < 0.01) and to be current smokers (someone who has smoked more than 100 cigarettes, including hand-rolled cigarettes, cigars, cigarillos, in their lifetime and has smoked in the last 28 days) (P < 0.01). The drop in terms of new diagnoses was greater in the lockdown period (percentage drop 1212% versus 123.2%) compared with the other months included. More LC pts were referred to a low/medium volume hospital in 2020 compared with 2019 (P = 0.01). No differences emerged in terms of interval between symptoms onset and radiological diagnosis (P = 0.94), symptoms onset and cytohistological diagnosis (P = 0.92), symptoms onset and treatment start (P = 0.40), and treatment start and first radiological revaluation (P = 0.36). Conclusions: Our study pointed out a reduction of new diagnoses with a shift towards higher stage at diagnosis for LC pts in 2020. Despite this, the measures adopted by Italian Oncology Departments ensured the maintenance of the diagnostic-therapeutic pathways of LC pts

Molecular alterations as target for therapy in metastatic osteosarcoma: a review of literature

Treating metastatic osteosarcoma (OS) remains a challenge in oncology. Current treatment strategies target the primary tumour rather than metastases and have a limited efficacy in the treatment of metastatic disease. Metastatic cells have specific features that render them less sensitive to therapy and targeting these features might enhance the efficacy of current treatment. A detailed study of the biological characteristics and behaviour of metastatic OS cells may provide a rational basis for innovative treatment strategies. The aim of this review is to give an overview of the biological changes in metastatic OS cells and the preclinical and clinical efforts targeting the different steps in OS metastases and how these contribute to designing a metastasis directed treatment for OS