An RNAi-based screen reveals PLK1, CDK1 and NDC80 as potential therapeutic targets in malignant pleural mesothelioma.

This corrects the article DOI: 10.1038/bjc.2017.85.

An RNAi-based screen reveals PLK1, CDK1 and NDC80 as potential therapeutic targets in malignant pleural mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is an aggressive tumour originating in the thoracic mesothelium. Prognosis remains poor with 9- to 12-month median survival, and new targets for treatments are desperately needed. METHODS: Utilising an RNA interference (RNAi)-based screen of 40 genes overexpressed in tumours, including genes involved in the control of cell cycle, DNA replication and repair, we investigated potential therapeutic targets for MPM. Following in vitro characterisation of the effects of target silencing on MPM cells, candidates were assessed in tumour samples from 154 patients. RESULTS: Gene knockdown in MPM cell lines identified growth inhibition following knockdown of NDC80, CDK1 and PLK1. Target knockdown induced cell-cycle arrest and increased apoptosis. Using small-molecule inhibitors specific for these three proteins also led to growth inhibition of MPM cell lines, and Roscovitine (inhibitor of CDK1) sensitised cells to cisplatin. Protein expression was also measured in tumour samples, with markedly variable levels of CDK1 and PLK1 noted. PLK1 expression in over 10% of cells correlated significantly with a poor prognosis. CONCLUSION: These results suggest that RNAi-based screening has utility in identifying new targets for MPM, and that inhibition of NDC80, CDK1 and PLK1 may hold promise for treatment of this disease.

Restoring expression of miR-16: a novel approach to therapy for malignant pleural mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is recalcitrant to treatment and new approaches to therapy are needed. Reduced expression of miR-15/16 in a range of cancer types has suggested a tumour suppressor function for these microRNAs, and re-expression has been shown to inhibit tumour cell proliferation. The miR-15/16 status in MPM is largely unknown. MATERIALS AND METHODS: MicroRNA expression was analysed by TaqMan-based RT-qPCR in MPM tumour specimens and cell lines. MicroRNA expression was restored in vitro using microRNA mimics, and effects on proliferation, drug sensitivity and target gene expression were assessed. Xenograft-bearing mice were treated with miR-16 mimic packaged in minicells targeted with epidermal growth factor receptor (EGFR)-specific antibodies. RESULTS: Expression of the miR-15 family was consistently downregulated in MPM tumour specimens and cell lines. A decrease of 4- to 22-fold was found when tumour specimens were compared with normal pleura. When MPM cell lines were compared with the normal mesothelial cell line MeT-5A, the downregulation of miR-15/16 was 2- to 10-fold. Using synthetic mimics to restore miR-15/16 expression led to growth inhibition in MPM cell lines but not in MeT-5A cells. Growth inhibition caused by miR-16 correlated with downregulation of target genes including Bcl-2 and CCND1, and miR-16 re-expression sensitised MPM cells to pemetrexed and gemcitabine. In xenograft-bearing nude mice, intravenous administration of miR-16 mimics packaged in minicells led to consistent and dose-dependent inhibition of MPM tumour growth. CONCLUSIONS: The miR-15/16 family is downregulated and has tumour suppressor function in MPM. Restoring miR-16 expression represents a novel therapeutic approach for MPM.

DLEC1 and MLH1 promoter methylation are associated with poor prognosis in non-small cell lung carcinoma.

The significance of chromosome 3p gene alterations in lung cancer is poorly understood. This study set out to investigate promoter methylation in the deleted in lung and oesophageal cancer 1 (DLEC1), MLH1 and other 3p genes in 239 non-small cell lung carcinomas (NSCLC). DLEC1 was methylated in 38.7%, MLH1 in 35.7%, RARbeta in 51.7%, RASSF1A in 32.4% and BLU in 35.3% of tumours. Any two of the gene alterations were associated with each other except RARbeta. DLEC1 methylation was an independent marker of poor survival in the whole cohort (P=0.025) and in squamous cell carcinoma (P=0.041). MLH1 methylation was also prognostic, particularly in large cell cancer (P=0.006). Concordant methylation of DLEC1/MLH1 was the strongest independent indicator of poor prognosis in the whole cohort (P=0.009). However, microsatellite instability and loss of MLH1 expression was rare, suggesting that MLH1 promoter methylation does not usually lead to gene silencing in lung cancer. This is the first study describing the prognostic value of DLEC1 and MLH1 methylation in NSCLC. The concordant methylation is possibly a consequence of a long-range epigenetic effect in this region of chromosome 3p, which has recently been described in other cancers.

Prognostic significance of DNA repair proteins MLH1, MSH2 and MGMT expression in non-small-cell lung cancer and precursor lesions.

AIMS: To investigate the role of DNA repair proteins and their prognostic significance in non-small-cell lung cancer (NSCLC). METHODS AND RESULTS: A retrospective analysis of 108 cases of stage I-II NSCLC was undertaken. Immunohistochemical expression of DNA repair proteins MLH1, MSH2 and MGMT was assessed using tissue microarrays of paraffin-embedded samples of invasive carcinoma and precursor lesions. Results were analysed in relation to clinicopathological parameters and patient survival. Reduced expression of MLH1 was found in 58.5% of tumours and occurred less frequently in poorly differentiated tumours (P = 0.044) and large cell carcinomas (P = 0.004). MSH2 and MGMT expression was reduced in 18.1% and 77.8% of cases, respectively. There was an inverse relationship between MLH1 and MSH2 expression (P = 0.012). Normal expression of MLH1, MSH2 and MGMT was found in all cases of squamous metaplasia and squamous dysplasia. Only a single case of carcinoma in situ (12.5%) showed reduced MLH1, none showed reduced MSH2 and 25% showed reduced MGMT. Survival analyses showed no prognostic significance based on expression of MLH1 (P = 0.92), MSH2 (P = 0.78) or MGMT (P = 0.57). CONCLUSIONS: Reduction in expression of DNA repair proteins MLH1, MSH2 and MGMT is relatively common in NSCLC, appears to be a late event in the development of invasive malignancy and does not influence survival in this patient cohort.

Phase II trial of carboplatin in the management of malignant mesothelioma.

Thirty-one patients with advanced malignant mesothelioma, previously untreated or having received only one prior cytotoxic regimen, were treated in a prospective, single-arm phase II trial with carboplatin (NSC 241240) at a dose of 150 mg/m2 per day intravenously (IV) for 3 days (450 mg/m2/course). One complete remission and four partial remissions were achieved, yielding an overall objective response rate of 16% (95% confidence interval [CI], 5.4% to 34%). The median duration of remission was 8 months (range, 5 to 17). Nonhematological toxicity was mild (only 12% with World Health Organization [WHO] grade 3 vomiting); 16% suffered WHO grade 3 to 4 hematological toxicity, but there were no life-threatening episodes and no treatment-related deaths. Carboplatin has modest activity against malignant mesothelioma and, because of its low toxicity, has a role in the management of this disease.

Bronchial carcinoids. Review of 124 cases.

A total of 124 patients with bronchial carcinoid were seen at Memorial Sloan-Kettering Cancer Center between 1949 and 1983. Of these, 68 were female and 56 were male. The age range was 12 to 82 years (median 55 years). Eleven of the tumors were incidental pathological findings at autopsy or operation and were excluded from survival data determinations. At the time of diagnosis, 82 patients had disease confined to the lung or bronchus, 19 had regional lymph node metastases, and 12 had distant metastases. Patients with distant metastases were more commonly male and smokers, and their tumors were mainly atypical carcinoids histologically, compared with those of patients with localized disease. Patients with distant disease were treated with external radiation and/or chemotherapy, and their median survival was 8 months. Of the 101 patients with disease localized to one hemithorax, endobronchial resection was performed in six and pulmonary resection in 95 (pneumonectomy 14, bilobectomy nine, lobectomy 52, sleeve resection five, segmentectomy 15). Recurrence following endobronchial resection was observed in four of six patients. Disease-free actuarial survival (calculated by the Kaplan-Meier method) following pulmonary resection was 92% at 5 years and 77% at 10 years. Factors predisposing to recurrence were tumor size greater than 3 cm (p less than 0.004), an atypical carcinoid on histologic study (p less than 0.001), and regional lymph node metastases (p = 0.01). Disease-free survival at 5 and 10 years in 19 patients who had regional lymphatic metastases was 74% and 53%, compared with 96% and 84% in those without lymphatic metastases. We conclude that (1) carcinoid tumors are malignant and 10% of patients present with metastases and (2) for patients with clinically localized tumors, the prognosis is determined by the size and histologic features of the tumor and the status of the regional lymph nodes, which must be assessed at thoracotomy.

Chest wall invasion in carcinoma of the lung. Therapeutic and prognostic implications.

From 1974 through 1983, 125 patients underwent operation at Memorial Sloan-Kettering Cancer Center for non-small cell carcinoma of the lung invading the chest wall. (Excluded are those with superior sulcus tumors or distant metastases at presentation.) Eighty patients were male and 45 were female. Ages ranged from 33 to 88 years (median 60 years). Histologically, the tumors were epidermoid carcinoma in 46%, adenocarcinoma in 46%, and large cell carcinoma in 8%. All patients underwent thoracotomy (pneumonectomy 19, bilobectomy seven, lobectomy 75, wedge resection 10, and no pulmonary resection 14), with an operative mortality of 4%. At thoracotomy, mediastinal lymph node dissection was routinely performed, and the postsurgical stage was T3 N0 M0 in 53%, T3 N1 M0 in 13%, and T3 N2 M0 in 34%. Extrapleural resection was performed in 66 patients. En bloc resection of chest wall and lung was performed in 45 patients with an operative mortality of 2%. Complete resection of tumor was possible in 77 patients (62%). Extension of tumor beyond the parietal pleura significantly decreased resectability. The median survival of 48 patients having incomplete resection was 9 months, despite perioperative interstitial and external radiation. The actuarial 5 year survival rate (Kaplan-Meier) of 77 patients having complete resection was 40%. This percentage was not significantly influenced by the patient's age or sex or by tumor size or histologic type. Lymphatic metastases significantly reduced survival, with a 5 year actuarial survival rate of 56% for patients with T3 N0 M0 disease and 21% for those with T3 N1 M0 or T3 N2 M0 disease (p = 0.005). The extent of tumor invasion of the chest wall appeared to influence survival, but in the absence of lymphatic metastases the difference at 5 years was not significant. Complete resection offers a significant chance for long-term survival in lung cancer directly extending into parietal pleura and chest wall. Extrapleural resection or en bloc chest wall resection can be performed with a low operative mortality and an expected 5 year survival in excess of 50% in the absence of lymphatic metastases.

Tetralogy of Fallot with absent pulmonary valve. Early and late results of surgical treatment.

From 1957 through September, 1983, 35 patients with tetralogy of Fallot and absent pulmonary valve underwent operation. Two subgroups of patients were recognized: minimally symptomatic (Group A, n = 21) and markedly symptomatic (Group B, n = 14). Group B patients were symptomatic at an earlier age and were younger at operation. Ages ranged from 1 day to 42 years (mean = 7.8 +/- 7.4 SD). Repair consisted of closure of the ventricular septal defect and relief of the right ventricle-pulmonary artery pressure gradient (nine patients received a tissue valve). In five patients, partial resection and/or plication of the aneurysmal pulmonary arteries also was performed. Operative mortality was 4.8% in Group A and 35.7% in Group B. In up to 25 years of follow-up, there was one late death in Group A (an early case with complete heart block); the remaining 19 patients are asymptomatic. In Group B, there were four late deaths, three related to cardiopulmonary insufficiency. These results indicate pulmonary valve insufficiency is tolerated well in minimally symptomatic patients. For markedly symptomatic patients, results may be improved if repair includes establishment of pulmonary valvular competence and reduction of size and length of aneurysmal pulmonary arteries.

Early and late results of pericardiectomy for constrictive pericarditis.

Records of 231 patients (171 males, 60 females; aged 10 months to 83 years [median 45 years]) who underwent operation for constrictive pericarditis at the Mayo Clinic from 1936 through 1982 were reviewed. All had had hemodynamically significant pericardial constriction preoperatively, and pericardial disease was confirmed at operation. Preoperatively, 69% were in New York Heart Association Class III or IV and 81% had peripheral edema or ascites. Pericardiectomy was performed through a left anterolateral thoracotomy (34%), a median sternotomy (27%), a U incision (Harrington) (21%), or a bilateral anterior thoracotomy (18%). Postoperatively, 28% of patients had evidence of low cardiac output; 70% of the 32 deaths within 30 days of operation were due to low cardiac output. Operative risk was significantly (p less than 0.001) related to preoperative disability (1% for Class I or II; 10% for class III; 46% for Class IV). Median postoperative follow-up was 9 years (longest was 43 years). Probability of survival for patients dismissed alive from the hospital was 84% at 5 years, 71% at 15 years, and 52% at 30 years. Long-term survival (excluding operative mortality) was not significantly influenced by the disability class preoperatively, the operative approach, or the development of low cardiac output in the immediate postoperative period. At the end of the follow-up interval, there were 141 patients in whom functional capacity could be assessed; 140 were in Class I or II. We conclude that a poor hemodynamic result after complete pericardiectomy relates to the preoperative degree of constriction and resultant cardiomyopathy. We recommend early pericardiectomy when pericardial constriction is diagnosed, and we continue to use a left anterolateral thoracotomy as the preferred approach for most patients.

Perforation of the esophagus by a fish bone leading to cardiac tamponade.

A 32-year-old woman swallowed a fish bone and presented to the hospital 3 days later with chest pain and fever. While in the hospital, she became hypotensive. A computed tomographic scan showed a fish bone penetrating from the esophagus into the pericardium. The fish bone was removed at urgent thoracotomy with immediate relief of her circulatory compromise. At the time of the operation, the fish bone was noted to be abrading the surface of the left atrium. We report this case of cardiac tamponade secondary to a perforated esophagus after foreign body ingestion.

Intrapleural bupivacaine in the control of postthoracotomy pain.

A randomized, double-blind trial was conducted to determine the effectiveness of intrapleural bupivacaine hydrochloride in the management of pain after thoracotomy. Thirty-three men and 7 women with a mean age of 62 years (range, 21 to 76 years) undergoing elective posterolateral thoracotomy were randomly allocated preoperatively to either a study group receiving 20 mL of 0.25% bupivacaine or a control group receiving 20 mL of 0.9% saline solution through a pleural catheter every 4 hours. Patients received supplementary doses of intramuscular papaveretum as required. Assessment of pain, somnolence, and breathing capacity was performed after the intrapleural injections at 4, 24, 48, and 72 hours postoperatively. Pain assessment, as measured by a linear analog scale, was lower in the bupivacaine group at all times, reaching significance at 4, 24, and 72 hours (p less than 0.05). The forced vital capacity and forced expiratory volume in 1 second at 6 weeks postoperatively remained significantly lower than preoperatively (p less than 0.05). The fall in forced vital capacity from this postoperative level was significantly less in the bupivacaine group at 4, 24, and 48 hours, and the fall in forced expiratory volume in 1 second was significantly less at 4 and 48 hours in the treated group. When used in conjunction with doses of parenteral narcotic, intrapleural bupivacaine gives better pain control with less respiratory depression than intermittent doses of narcotic alone.

Thymoma: trends over time.

BACKGROUND: This is a review of a series of patients who presented with thymoma over the most recent 20-year period. Changes and trends in disease patterns were documented. METHODS: Data were collated retrospectively but all pathology slides were reviewed. Survival functions were estimated using the Kaplan-Meier method. RESULTS: Seventy-one patients had a partial or total thymectomy during this period for a thymoma. Average age was 55 years. Twenty-three patients (32%) had myaesthenia gravis. Eighteen patients (25%) were asymptomatic. Thirty-three patients (47%) had stage 1 disease. Complete resection was achieved in 60 patients (85%). Five-year survival was 88%. Fifty percent of patients with myesthenia gravis showed improvement in symptoms. CONCLUSIONS: Five- and 10-year survival rates in this study are better than in other series. We attribute this to an increasing number of patients with stage 1 and stage 2 disease, particularly those with myasthenia gravis who now have screening computer tomography, and also to the surgical intent of aiming to achieve complete resection even if excision of adjacent tissue is required.

Mitral valve replacement combined with coronary artery operation: determinants of early and late results.

Mitral valve replacement combined with coronary artery bypass grafting has been reported as being associated with a higher mortality than either mitral valve replacement or coronary artery bypass grafting alone. Cause of mitral valve disease and severity of mitral regurgitation have been reported as related to mortality. To study the correlation of the cause of mitral valve disease and severity of mitral regurgitation to hospital mortality and long-term survival, we analyzed the results of 135 patients undergoing mitral valve replacement and coronary artery bypass grafting between June 1974 and August 1989. The hospital mortality was 11.8% (16/135). Fifteen preoperative and operative variables were tested for correlation with hospital or late mortality using univariate tests and multivariate regression. Advanced age (greater than 60 years), New York Heart Association functional class, and wall motion score were independently associated with hospital mortality (p less than 0.05). The cause of mitral valve disease and severity of mitral regurgitation were not related to hospital mortality or long-term survival (p greater than 0.05). The follow-up rate was 96.6% for the hospital survivors (115/119). Mean follow-up was 52.6 +/- 4.1 months. There were 35 late deaths. Survival was 91.9%, 89.9%, 78%, and 49.9% at 1, 2, 5, and 10 postoperative years, respectively. Preoperative New York Heart Association functional class and use of catecholamines during the postoperative intensive care period were independently related to late survival (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary metastatic melanoma -- the survival benefit associated with positron emission tomography scanning.

OBJECTIVE: Positron emission tomography (PET) scanning is more sensitive at detecting metastatic disease than conventional radiological techniques. For patients with pulmonary metastatic melanoma, we investigate if PET scanning to detect occult extra pulmonary disease prior to thoracotomy and metastectomy is associated with improved survival compared to patients staged by conventional radiology. METHODS: Between November 1984 and December 1999, 121 patients (90 males, 31 females) have undergone a thoracotomy and pulmonary metastectomy for metastatic melanoma. The age range was 19-84 years (mean 57, median 59). In every case all palpable nodules were removed and the diagnosis confirmed histologically. A total of 68 (56%) patients had a PET scan preoperatively, 53 (44%) underwent conventional or nuclear imaging. Patients with only radiologically isolated pulmonary disease are included. RESULTS: Survival is 100% complete and totals 238 pt/years (mean 2.2 years, median 1.4 years). Survival (+/-SE) at 1, 3, 5 and 7 years for all patients is 68% (+/-4.5) (n=67), 36.6% (+/-5.2) (n=27), 22.1% (+/-4.8) (n=15) and 13.5% (+/-4.2) (n=7), respectively. Survival (+/-SE) was significantly better at 3 and 5 years in patients who underwent a PET scan preoperatively (Log rank P=0.002). There was no significant difference in survival by 7 years. CONCLUSIONS: There is a significant survival benefit associated with excluding extra pulmonary disease using a PET scan prior to thoracotomy and metastectomy. We recommend that PET scanning be used in the investigation of patients with pulmonary metastatic melanoma prior to metastectomy.

Surgical resection for pulmonary metastases from colorectal cancer.

BACKGROUND: Isolated pulmonary metastases from colorectal cancer are rare. The present study reports on the 15-year experience of the Royal Prince Alfred Unit and discusses means of improving survival outcomes. METHODS: This was a retrospective review, over a 15-year period, of 41 patients who had resectable pulmonary metastases of colorectal origin. RESULTS: Most were asymptomatic at the time of diagnosis. Seventy-two per cent had solitary metastases. The most common procedure performed was a lobectomy. Median follow up was 21 months. Five-year survival was 24%. There were no significant prognostic indicators except for the ability to achieve clear surgical margins. CONCLUSION: Morbidity and mortality have not altered significantly over time. But an improved selection process such as the use of preoperative positron emission tomography will potentially improve survival outcomes.

Anesthesia for tracheal stenosis, tracheoesophageal fistula and status asthmaticus.

A 26-year-old female patient who, in addition to tracheal stenosis, also suffered from status asthmaticus and an esophagotracheal fistula, underwent surgery for resection of the stenosed segment, reconstruction of tracheal continuity and fistula repair. The therapy for her asthma and the anesthetic management for bronchoscopy and, later, definitive surgery are described. Radiological photographs (before and after surgery) as well as results of respiratory function tests are shown.

Coronary artery surgery in an indigenous Papua New Guinean male.

The first case of coronary artery surgery in an indigenous Papua New Guinean male subject is described. A 42-year-old male with multiple risk factors developed two episodes of myocardial infarction. Coronary arteriography demonstrated severe obstructive disease in all three coronary arteries with moderate left ventricular dysfunction. Prognostic coronary revascularization was performed, with placement of four bypass grafts with six distal anastomoses. Recovery was largely uncomplicated. Maximal exercise test 6 months postoperatively showed normal exercise capacity with no evidence of ischaemia. He is pursuing an intensive program of risk factor management.

Phosphorylated Akt expression is a prognostic marker in early-stage non-small cell lung cancer.

AIMS: To determine the prognostic significance of pAkt expression in order to identify high-risk stage IB patients with non-small cell lung cancer (NSCLC) in an exploratory study. METHODS: We identified 471 consecutive patients with stage IB primary NSCLC according to the American Joint Commission on Cancer 6th edition tumour-node-metastasis (TNM) staging system, who underwent surgical resection between 1990 and 2008. Patients who received neoadjuvant or adjuvant treatments were excluded. Pathology reports were reviewed, and pathological characteristics were extracted. Expression of phosphorylated Akt (pAkt) in both cytoplasmic and nuclear locations was assessed by immunohistochemistry, and clinicopathological factors were analysed against 10-year overall survival using Kaplan-Meier and Cox proportional hazards model. RESULTS: 455 (96.6%) cancers were adequate for pAkt immunohistochemical analysis. The prevalence of pAkt expression in the cytoplasm and nucleus of the cancers was 60.7% and 43.7%, respectively. Patients whose cancers expressed higher levels of cytoplasmic pAkt had a trend towards longer overall survival than those with lower levels (p=0.06). Conversely, patients whose cancers expressed higher levels of nuclear pAkt had a poorer prognosis than those with lower levels of expression (p=0.02). Combined low cytoplasmic/high nuclear expression of pAkt was an independent predictor of overall survival (HR=2.86 (95% CI 1.35 to 6.04); p=0.006) when modelled with age (HR=1.05 (95% CI 1.03 to 1.07); p<0.001), extent of operation (HR=2.11 (95% CI 1.48 to 3.01); p<0.001), visceral pleural invasion (HR=1.63 (95% CI 1.24 to 2.15); p<0.001), gender, tumour size, histopathological type and grade (p>0.05). CONCLUSIONS: Level of expression of pAkt in the cytoplasm and nucleus is an independent prognostic factor that may help to select patients with high-risk disease.