Biomarkers and prognostic factors for mesothelioma

Pan-cancer analysis of cuproptosis-promoting gene signature from multiple perspectives

Cuproptosis is a newly discovered cell death form with a unique mechanism. Seven genes have been identified to facilitate the process. To explore the roles of cuproptosis in different cancers, we first used Gene Expression Profiling, Interactive Analysis, version 2, and cBioPortal to analyze expression, prognosis and mutation conditions in different cancers from The Cancer Genome Atlas (TCGA). Then, we conducted single sample gene set enrichment analysis to combine the signature of the cuproptosis-promoting genes for all TCGA cancers. Moreover, we performed a survival analysis to explore if cuproptosis-score could independently influence clinical outcomes. Next, we compared pathway enrichment, immune infiltration, gene set activity and gene mutation between different cuproptosis-score groups. Finally, based on the intersected genes from difference analysis and weighted gene co-expression network analysis, consensus clustering and Least Absolute Shrinkage and Selection Operator Cox regression were performed and nomograms were constructed. Cuproptosis-score was associated with a favorable prognosis in eight TCGA cancers. Cancer-associated fibroblasts, B cells, neutrophils and mast cells were generally less abundant, and ferroptosis activity was higher in high cuproptosis-score groups. The novel classifications could differentiate patients' overall survival, and the risk models could effectively predict patients' outcomes in kidney, renal clear cell carcinoma, liver hepatocellular carcinoma, mesothelioma and stomach adenocarcinoma. Cuproptosis activity was closely related to the prognosis of several cancers. Its effects on the immune microenvironment and its relationship with other cell death modes, especially ferroptosis, may become the focus of further research.

Malignant pleural mesothelioma: clinical experience and prognostic value of derived neutrophil-to-lymphocyte ratio and PD-L1 expression

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor, with a poor prognosis. MPM needs to find prognostic factors of survival. We provided the management of patients with MPM and sought to determine whether pre-treatment levels of derived neutrophil-to-lymphocyte ratio (dNLR) as well as PD-L1 expression were reliable prognostic factors of survival.

METHODS

We conducted a single-institution retrospective study, including all patients with MPM treated at La Paz University Hospital between December 2009 and March 2018. Baseline disease, demographics, clinical data, treatment characteristics and complete blood cell counts were collected. We examined dNLR at baseline and data for PD-L1 expression were analyzed in tumor cells by immunohistochemistry.

RESULTS

We included 25 patients. The median overall survival (OS) was 15.7 months (95% CI 11.3-20.0). 5 patients had a dNLR greater than 3 (20%). Patients with a dNLR greater than 3 had shorter median OS (8.5 months), than patients with a dNLR less than 3 (17.0 months), with statistically significant differences (p = 0.038). Ten patients (40%) had positive PD-L1 expression (≥ 1%). Patients with positive PD-L1 expression had shorter median OS (8.5 months) than patients with negative PDL1 expression (15.7 months), but without statistically significant association (p = 0.319).

CONCLUSION

The survival data obtained in our sample are consistent with those previously reported. Pretreatment levels of dNLR greater than 3 and positive PD-L1 expression could be significant prognostic factors for poor survival in patients with MPM. Further and prospective studies are needed to explore this relationship and to derive definitive conclusions.

Elevated Serum Megakaryocyte Potentiating Factor as a Predictor of Poor Survival in Patients with Mesothelioma and Primary Lung Cancer

Background

There is an urgent need for a companion assay to work with mesothelin-targeted therapeutic agents and for noninvasive and accurate prognostication of malignant mesothelioma (MM) patients. We report the development and validation of a blood-based assay for megakaryocyte potentiating factor (MPF) and the evaluation of its effectiveness for prognosis in MM and lung cancer patients.

Methods

Using electrochemiluminescence technology, we developed a sensitive MPF assay and performed both analytical and clinical validations. Further, the effectiveness of the MPF assay in predicting prognosis was evaluated for 95 MM and 272 lung cancer patients.

Results

We performed comprehensive analytical and clinical validation, including precision and accuracy, interference, preanalytical variables, sensitivity, and specificity for mesothelioma. In MM patients, increased serum MPF is a predictor of poor survival with a hazard ratio (HR) = 2.46 (log-rank P = 0.003; n = 95). In refractory MM patients, increased MPF is a strong predictor of poor outcome with an HR = 6.12 (log-rank P = 0.0007; n = 57). In a lung cancer patient cohort, increased MPF is a predictor of poor survival, with an HR = 1.57 (log-rank P = 0.003; n = 272).

Conclusions

The MPF assay has robust technical characteristics, with strong analytic and clinical validation. Clinical studies indicate that increased serum MPF is a predictor of poor survival for MM patients, throughout the course of the disease. Increased MPF is also associated with poor overall survival for patients with newly diagnosed lung cancer.

Genomics and Epigenetics of Malignant Mesothelioma

Malignant mesothelioma is an aggressive and lethal asbestos-related disease. Diagnosis of malignant mesothelioma is particularly challenging and is further complicated by the lack of disease subtype-specific markers. As a result, it is especially difficult to distinguish malignant mesothelioma from benign reactive mesothelial proliferations or reactive fibrosis. Additionally, mesothelioma diagnoses can be confounded by other anatomically related tumors that can invade the pleural or peritoneal cavities, collectively resulting in delayed diagnoses and greatly affecting patient management. High-throughput analyses have uncovered key genomic and epigenomic alterations driving malignant mesothelioma. These molecular features have the potential to better our understanding of malignant mesothelioma biology as well as to improve disease diagnosis and patient prognosis. Genomic approaches have been instrumental in identifying molecular events frequently occurring in mesothelioma. As such, we review the discoveries made using high-throughput technologies, including novel insights obtained from the analysis of the non-coding transcriptome, and the clinical potential of these genetic and epigenetic findings in mesothelioma. Furthermore, we aim to highlight the potential of these technologies in the future clinical applications of the novel molecular features in malignant mesothelioma.

A Novel Panel of Serum Biomarkers for MPM Diagnosis

Exposure to asbestos is the main cause of malignant pleural mesothelioma (MPM), a highly aggressive cancer of the pleura. Since the only tools for early detection are based on radiological tests, some authors focused on serum markers (i.e., mesothelin). The aim of this study was the evaluation of new serum biomarkers to be used individually or in combination, in order to improve the outcome of patients whose disease would be diagnosed at an earlier stage. Serum and plasma were available from 43 subjects previously exposed to asbestos and 27 MPM patients, all being epithelioid type. All the new markers found differentially expressed in MPM and healthy subjects, by proteomic and genomic approaches, have been validated in the serum by the use of specific ELISA. The combined approach, using tools of genomics and proteomics, is found to be highly innovative for this type of disease and led to the identification of new serum markers in the diagnosis of MPM. These results, if confirmed in a larger series, may have a strong impact in this area, because early detection of this cancer in people at high risk could significantly improve the course of the disease and the clinical approach to an individualized therapy.

Management of malignant pleural mesothelioma - part 1: epidemiology, diagnosis, and staging : Consensus of the Austrian Mesothelioma Interest Group (AMIG)

Malignant pleural mesothelioma is a rare malignant disease that in the majority of cases is associated with asbestos exposure. The incidence in Europe is about 20 per million inhabitants and it is increasing worldwide. Initial symptoms are shortness of breath, pleural effusion, cough, and chest pain. The typical growth pattern is along the pleural surface; however, infiltration of the lung and/or mediastinal and chest wall structures can occur in a more advanced stage. Ultimately, distant metastases outside the chest can result. Several histological subtypes of pleural mesothelioma exist, which must be differentiated from either benign diseases or metastases in the pleural space by other tumor entities. This differential diagnosis can be very difficult and a large panel of immunohistochemical markers is required to establish the exact diagnosis. The standard procedure for confirming the disease and obtaining sufficient tissue for the diagnosis is videothoracoscopy. Full thickness biopsies are required, while transthoracic needle puncture of pleural fluid or tissue is considered to be insufficient for a cytological diagnosis. Complete and detailed staging is mandatory for categorization of the disease as well as for therapeutic decision making.

MicroRNA‑21 regulates the expression of BTG2 in HepG2 liver cancer cells

B-cell translocation gene 2 (BTG2) is a tumor suppressor gene, which belongs to the anti-proliferation gene family. Our previous study demonstrated that microRNA (miR)-21 and the expression of BTG2 were negatively correlated during hepatocarcinogenesis. The aim of the present study was to investigate the effects of miR-21 on the growth and progression of liver cancer cells, and to determine the underlying mechanism. A luciferase reporter assay was used to demonstrate that the BTG2 gene was a direct target of miR-21. In addition, the effects of miR-21 on cell growth and gene expression in HepG2 human hepatocellular carcinoma (HCC) cells were analyzed using reverse transcription-quantitative polymerase chain reaction, western blotting, an MTT assay, flow cytometry, a Transwell invasion assay and a wound healing assay. The expression levels of miR-21 in the HepG2 cells were significantly higher, compared with those in L02 normal liver cells. The expression levels of BTG2 in liver cancer cell lines (HepG2 and Huh7) were significantly lower, compared with that in the L02 cells. These results suggested that BTG2 was the direct target gene of miR-21. The protein expression levels of BTG2 were inhibited by high expression levels of miR-21, and increased by inhibition of the expression of miR-21 in the HepG2 cells. Inhibition of miR-21 reduced cell proliferation and invasion, and increased the rate of apoptosis in the HepG2 cells. These results indicated that miR-21 regulates cell proliferation, invasion, migration and apoptosis in HepG2 cells, which may be associated with its effects on the expression of BTG2. The results of the present study may provide a basis for targeting the miR-21/BTG2 interaction for the treatment of HCC.

MiR-score: a novel 6-microRNA signature that predicts survival outcomes in patients with malignant pleural mesothelioma

BACKGROUND

Prognosis of malignant pleural mesothelioma (MPM) is poor, and predicting the outcomes of treatment is difficult. Here we investigate the potential of microRNA expression to estimate prognosis of MPM patients.

METHODS

Candidate microRNAs from microarray profiling of tumor samples from 8 long (median: 53.7 months) and 8 short (median: 6.4 months) survivors following extrapleural pneumonectomy (EPP) were validated by RT-qPCR in 48 additional EPP samples. Kaplan-Meier log ranking was used to further explore the association between microRNA expression and overall survival (OS). Binary logistic regression was used to construct a microRNA signature (miR-Score) that was able to predict an OS of ≥20 months. Performance of the miR-Score was evaluated by receiver operating characteristic (ROC) curve analysis and validated in a series of 43 tumor samples from patients who underwent palliative surgery [pleurectomy/decortication (P/D)].

RESULTS

The miR-Score, using expression data of six microRNAs (miR-21-5p, -23a-3p, -30e-5p, -221-3p, -222-3p, and -31-5p), enabled prediction of long survival with an accuracy of 92.3% for EPP and 71.9% for palliative P/D. Hazard ratios for score-negative patients were 4.12 (95% CI: 2.03-8.37) for EPP and 1.93 (95% CI: 1.01-3.69) for P/D. Importantly, adding the miR-Score to a set of clinical selection criteria (histology, age, gender) increased predictive accuracy in the independent validation set from 76.3% for clinical factors only to 87.3%.

CONCLUSIONS

This study has identified a novel 6-microRNA signature (miR-Score) that can accurately predict prognosis of MPM patients.

Supplementary prognostic variables for pleural mesothelioma: a report from the IASLC staging committee

INTRODUCTION

The staging system for malignant pleural mesothelioma is controversial. To revise this system, the International Association for the Study of Lung Cancer Staging Committee developed an international database. This report analyzes prognostic variables in a surgical population, which are supplementary to previously published CORE variables (stage, histology, sex, age, and type of procedure).

METHODS

Supplementary prognostic variables were studied in three scenarios: (1) all data available, that is, patient pathologically staged and other CORE variables available (2) only clinical staging available along with CORE variables, and (3) only age, sex, histology, and laboratory parameters are known. Survival was analyzed by Kaplan-Meier, prognostic factors by log rank and stepwise Cox regression modeling after elimination of nonsignificant variables. p value less than 0.05 was significant.

RESULTS

A total of 2141 patients with best tumor, node, metastasis (TNM) stages (pathologic with/without clinical staging) had nonmissing age, sex, histology, and type of surgical procedure. Three prognostic models were defined. Scenario A (all parameters): best pathologic stage, histology, sex, age, type of surgery, adjuvant treatment, white blood cell count (WBC) (≥15.5 or not), and platelets (≥400 k or not) (n = 550). Scenario B (no surgical staging): clinical stage, histology, sex, age, type of surgery, adjuvant treatment, WBC, hemoglobin (<14.6 or not), and platelets (n = 627). Scenario C (limited data): histology, sex, age, WBC, hemoglobin, and platelets (n = 906).

CONCLUSION

Refinement of these models could define not only the appropriate patient preoperatively for best outcomes after cytoreductive surgery but also stratify surgically treated patients after clinical and pathologic staging who do or do not receive adjuvant therapy.

Hyponatraemia is a predictor of clinical outcome for malignant pleural mesothelioma

PURPOSE

Hyponatraemia is one of the most common tumour-related electrolyte disorders. Several clinical, histological and serum factors have been found to influence prognosis, but, to date, there are no studies focusing on the prognostic role of hyponatraemia in mesothelioma. The aim of this study was to assess the prognostic role of hyponatraemia in malignant pleural mesothelioma.

METHODS

We analysed 62 consecutive patients with histologically or cytologically proven advanced malignant pleural mesothelioma undergoing chemotherapy at our institution between January 2003 and September 2013.

RESULTS

All patients received a first-line pemetrexed-based chemotherapy. A second-line chemotherapy was administered to 29 patients. The onset of hyponatraemia (serum sodium <135 mEq/L) during the treatment was significantly related to a worsened median overall survival (7.93 vs 13.48 months; p = 0.0069). The occurrence of hyponatraemia during first-line chemotherapy (cutoff 135 and 130 mEq/L) was significantly associated to a shorter median progression-free survival (p = 0.0214). Results were also similar in the subgroup receiving a second-line treatment. At the multivariate analysis, including haemoglobin and sodium level at the beginning of first-line chemotherapy, age, gender, smoking habit, job exposure and performance status, only hyponatraemia was found to be an independent factor (p = 0.029). Hyponatraemia was also found to be a predictive factor for both first-line chemotherapy, being related to poorer response to pemetrexed-based chemotherapy (p = 0.047) and second-line chemotherapy (p = 0.044).

CONCLUSION

Our results show that hyponatraemia might be considered a negative prognostic parameter in malignant pleural mesothelioma patients. To our knowledge, this is the first study to evaluate the association of hyponatraemia with the outcome of malignant pleural mesothelioma patients.

Expression and significance of miRNA-21 and BTG2 in lung cancer

This study investigates the expression of micro-ribonucleic acid-21 (miRNA-21) and B cell translocation gene 2 (BTG2) in lung cancer cells. We examined the impact of miRNA-21 on biological characteristics of lung cancer cells, such as growth, proliferation, apoptosis, and invasion. The expression of miRNA-21 and BTG2 protein in lung cancer cell lines (A549, HCC827, NCI-H292, and 95-D) was examined using quantitative reverse transcription-polymerase chain reaction and Western blot analysis, respectively. Subsequently, the regulatory role of miRNA-21 on BTG2 was explored by inhibiting miRNA-21 expression in 95-D cells using miRNA-21-antisense oligonucleotides (miRNA-21 ASO). The impact of miRNA-21 on the biological characteristics of 95-D cells was further studied using methylthiazol tetrazolium assays, flow cytometry, and Transwell invasion chamber assays. The impact of miRNA-21 on the expression of cyclin D1, caspase-3, and matrix metalloprotease-9 (MMP9) was also studied. miRNA-21 expression was significantly higher in lung cancer cell lines (A549, HCC827, NCI-H282, and 95-D) than that in normal human bronchial epithelial cells (HBE; p < 0.05). The pattern of BTG2 protein expression was exactly the opposite of miRNA-21 expression in lung cancer cells. BTG2 was highly expressed in HBE cells and was expressed at very low levels in lung cancer cell lines (A549, HCC827, NCI-H292, and 95-D). High miRNA-21 expression may inhibit BTG2 protein expression, whereas the inhibition of miRNA-21 expression may promote BTG2 protein expression in 95-D cells. Cell viability and invasion of 95-D cells were significantly lower in the miRNA-21 ASO-transfected group than that in the control ASO-transfected group and untransfected group (p < 0.05). The number of apoptotic cells was significantly higher in the miRNA-21 ASO-transfected group than that in the control ASO-transfected and untransfected groups (p < 0.05). The expression level of cyclin D1 and MMP9 in 95-D cells was significantly lower in the miRNA-21 ASO-transfected group than in the control ASO-transfected and untransfected groups (p < 0.05). Meanwhile, caspase-3 expression was significantly higher in the miRNA-21 ASO-transfected group than that in the control ASO-transfected and untransfected groups (p < 0.05). miRNA-21 overexpression may inhibit the BTG2 gene in lung cancer cells. miRNA-21 may promote cell proliferation and invasion and inhibit cell apoptosis in 95-D cells.

The challenge of prognostic markers in pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a very aggressive tumor, highly resistant to chemo- and radio-therapy. Treatment of MPM patients is often disappointing, regardless of the modality used. Inter-individual variability of response to multimodal treatment remains a challenge and generally the MPM prognosis continues to be poor. Knowledge of predicting factors of outcome is currently insufficient; therefore, it would be highly desirable to find specific prognostic markers for MPM. Translational research projects are to be implemented.