Patient-derived xenograft (PDX) mouse models are increasingly used for preclinical therapeutic testing of human cancer. A limitation in molecular and genetic characterization of PDX tumors is the ...presence of integral murine stroma. This is particularly problematic for genomic sequencing of PDX models. Rapid and dependable approaches for quantitating stromal content and purifying the malignant human component of these tumors are needed. We used a recently developed technique exploiting species-specific polymerase chain reaction (PCR) amplicon length (ssPAL) differences to define the fractional composition of murine and human DNA, which was proportional to the fractional composition of cells in a series of lung cancer PDX lines. We compared four methods of human cancer cell isolation: fluorescence-activated cell sorting (FACS), an immunomagnetic mouse cell depletion (MCD) approach, and two distinct EpCAM-based immunomagnetic positive selection methods. We further analyzed DNA extracted from the resulting enriched human cancer cells by targeted sequencing using a clinically validated multi-gene panel. Stromal content varied widely among tumors of similar histology, but appeared stable over multiple serial tumor passages of an individual model. FACS and MCD were superior to either positive selection approach, especially in cases of high stromal content, and consistently allowed high quality human-specific genomic profiling. ssPAL is a dependable approach to quantitation of murine stromal content, and MCD is a simple, efficient, and high yield approach to human cancer cell isolation for genomic analysis of PDX tumors.
The high-grade pulmonary neuroendocrine tumors, small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC), remain among the most deadly malignancies. Therapies that effectively ...target and kill tumor-initiating cells (TICs) in these cancers should translate to improved patient survival. Patient-derived xenograft (PDX) tumors serve as excellent models to study tumor biology and characterize TICs. Increased expression of delta-like 3 (DLL3) was discovered in SCLC and LCNEC PDX tumors and confirmed in primary SCLC and LCNEC tumors. DLL3 protein is expressed on the surface of tumor cells but not in normal adult tissues. A DLL3-targeted antibody-drug conjugate (ADC), SC16LD6.5, comprised of a humanized anti-DLL3 monoclonal antibody conjugated to a DNA-damaging pyrrolobenzodiazepine (PBD) dimer toxin, induced durable tumor regression in vivo across multiple PDX models. Serial transplantation experiments executed with limiting dilutions of cells provided functional evidence confirming that the lack of tumor recurrence after SC16LD6.5 exposure resulted from effective targeting of DLL3-expressing TICs. In vivo efficacy correlated with DLL3 expression, and responses were observed in PDX models initiated from patients with both limited and extensive-stage disease and were independent of their sensitivity to standard-of-care chemotherapy regimens. SC16LD6.5 effectively targets and eradicates DLL3-expressing TICs in SCLC and LCNEC PDX tumors and is a promising first-in-class ADC for the treatment of high-grade pulmonary neuroendocrine tumors.
We assessed the efficacy of Seneca Valley virus (SVV-001), a neuroendocrine cancer-selective oncolytic picornavirus, in primary heterotransplant mouse models of small cell lung cancer (SCLC), ...including three lines each of classic and variant SCLC. Half-maximal effective concentrations for cell lines derived from three variant heterotransplants ranged from 1.6×10(-3) (95% confidence interval CI = 1×10(-3) to 2.5×10(-3)) to 3.9×10(-3) (95% CI = 2.8×10(-3) to 5.5×10(-3)). Sustained tumor growth inhibition in vivo was only observed in variant lines (two-sided Student t test, P < .005 for each). Doses of 10(14) vp/kg were able to completely and durably eradicate tumors in a variant SCLC heterotransplant model in two of six mice. Gene expression profiling revealed that permissive lines are typified by lower expression of the early neurogenic transcription factor ASCL1 and, conversely, by higher expression of the late neurogenic transcription factor NEUROD1. This classifier demonstrates a sensitivity of .89, specificity of .92, and accuracy of .91. The NEUROD1 to ASCL1 ratio may serve as a predictive biomarker of SVV-001 efficacy.
Small cell lung cancer (SCLC) is an aggressive malignancy characterized by early metastasis, rapid development of resistance to chemotherapy and genetic instability. This study profiles DNA ...methylation in SCLC, patient-derived xenografts (PDX) and cell lines at single-nucleotide resolution. DNA methylation patterns of primary samples are distinct from those of cell lines, whereas PDX maintain a pattern closely consistent with primary samples. Clustering of DNA methylation and gene expression of primary SCLC revealed distinct disease subtypes among histologically indistinguishable primary patient samples with similar genetic alterations. SCLC is notable for dense clustering of high-level methylation in discrete promoter CpG islands, in a pattern clearly distinct from other lung cancers and strongly correlated with high expression of the E2F target and histone methyltransferase gene EZH2. Pharmacologic inhibition of EZH2 in a SCLC PDX markedly inhibited tumor growth.
Approximately 30% of early-stage lung adenocarcinoma patients present with disease progression after successful surgical resection. Despite efforts of mapping the genetic landscape, there has been ...limited success in discovering predictive biomarkers of disease outcomes. Here we performed a systematic multi-omic assessment of 143 tumors and matched tumor-adjacent, histologically-normal lung tissue with long-term patient follow-up. Through histologic, mutational, and transcriptomic profiling of tumor and adjacent-normal tissue, we identified an inflammatory gene signature in tumor-adjacent tissue as the strongest clinical predictor of disease progression. Single-cell transcriptomic analysis demonstrated the progression-associated inflammatory signature was expressed in both immune and non-immune cells, and cell type-specific profiling in monocytes further improved outcome predictions. Additional analyses of tumor-adjacent transcriptomic data from The Cancer Genome Atlas validated the association of the inflammatory signature with worse outcomes across cancers. Collectively, our study suggests that molecular profiling of tumor-adjacent tissue can identify patients at high risk for disease progression.
Aim
Sarcopenia, or a reduction of lean muscle mass, is associated with poorer outcomes in cancer patients. Few previous studies have examined this potentially correctable risk factor in patients with ...locally advanced rectal cancer.
Method
Skeletal muscle mass index was measured retrospectively on initial staging CT scans of patients undergoing chemoradiation followed by radical resection for rectal cancer for the period 2007–2013. Patients were categorized as sarcopenic or nonsarcopenic and differences in terms of demographics, pre‐, peri‐ and postoperative outcomes were examined.
Results
Forty‐seven patients were included; their mean age was 59.3 (36–82) years and 61.7% were men. We considered that 55.2% of men and 44.4% of women were sarcopenic; the overall prevalence of sarcopenia was 51.1%. Age, preoperative haemoglobin and albumin were significantly related to sarcopenia. Body mass index (BMI) and obesity (BMI > 30 kg/m2) were not associated with sarcopenia. Blood transfusions were more frequent in sarcopenic patients (P = 0.001). Although readmissions and length of stay were not increased, overall postoperative complications were significantly higher in sarcopenic patients (P = 0.03). Neither BMI nor obesity was associated with postoperative complications.
Conclusion
Sarcopenia was present in over 50% of patients with locally advanced rectal cancer at diagnosis. It was associated with a higher incidence of both blood transfusion and postoperative complications. BMI did not correlate with these negative outcomes. Sarcopenia may be a better predictor of surgical outcomes than BMI or obesity.
Although lung disease is the primary clinical outcome in COVID-19 patients, how SARS-CoV-2 induces lung pathology remains elusive. Here we describe a high-throughput platform to generate ...self-organizing and commensurate human lung buds derived from hESCs cultured on micropatterned substrates. Lung buds resemble human fetal lungs and display proximodistal patterning of alveolar and airway tissue directed by KGF. These lung buds are susceptible to infection by SARS-CoV-2 and endemic coronaviruses and can be used to track cell type-specific cytopathic effects in hundreds of lung buds in parallel. Transcriptomic comparisons of infected lung buds and postmortem tissue of COVID-19 patients identified an induction of BMP signaling pathway. BMP activity renders lung cells more susceptible to SARS-CoV-2 infection and its pharmacological inhibition impairs infection by this virus. These data highlight the rapid and scalable access to disease-relevant tissue using lung buds that recapitulate key features of human lung morphogenesis and viral infection biology.
•Derivation of self-organizing and commensurate lung buds on microchips from hESCs•Lung buds display in vivo-like proximo-distal patterning of lung tissue•Parallelized quantitative analysis of SARS-CoV-2 viral life cycle in lung buds•Identification of BMP signaling as a key mediator of SARS-CoV-2 infection via ACE2
Brivanlou and colleagues describe a high-throughput platform to generate self-organizing human lung buds from hESCs on microchips. Lung buds display in vivo-like proximo-distal patterning of lung tissue, and are amenable to high-throughput quantitative analysis of SARS-CoV-2 cell type-specific infection, transmission, and cytopathology. Transcriptomic comparisons with COVID-19 postmortem tissues identified the BMP signaling pathway as a key regulator of SARS-CoV-2 infection.
Implantable left ventricular assist devices have benefited patients with end-stage heart failure as a bridge to cardiac transplantation, but their long-term use for the purpose of enhancing survival ...and the quality of life has not been evaluated.
We randomly assigned 129 patients with end-stage heart failure who were ineligible for cardiac transplantation to receive a left ventricular assist device (68 patients) or optimal medical management (61). All patients had symptoms of New York Heart Association class IV heart failure.
Kaplan-Meier survival analysis showed a reduction of 48 percent in the risk of death from any cause in the group that received left ventricular assist devices as compared with the medical-therapy group (relative risk, 0.52; 95 percent confidence interval, 0.34 to 0.78; P=0.001). The rates of survival at one year were 52 percent in the device group and 25 percent in the medical-therapy group (P=0.002), and the rates at two years were 23 percent and 8 percent (P=0.09), respectively. The frequency of serious adverse events in the device group was 2.35 (95 percent confidence interval, 1.86 to 2.95) times that in the medical-therapy group, with a predominance of infection, bleeding, and malfunction of the device. The quality of life was significantly improved at one year in the device group.
The use of a left ventricular assist device in patients with advanced heart failure resulted in a clinically meaningful survival benefit and an improved quality of life. A left ventricular assist device is an acceptable alternative therapy in selected patients who are not candidates for cardiac transplantation.
In this issue of Cancer Discovery, Romero and colleagues identify somatic mutations and deletions of MAX, and also define what seem to be mutually exclusive alterations in MYC family members and ...other MYC-associated factors in small cell lung cancer. Taken together, these data highlight the importance of MYC signaling in small cell lung cancer and suggest possible avenues for therapeutic intervention.
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