The quantitative range and reproducibility of current serological tests for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are not optimized. Herein, we developed a diagnostic test that ...detects SARS-CoV-2 IgG and IgM with high quantitativeness and reproducibility and low interference. The system was based on the high-sensitivity chemiluminescence enzyme immunoassay (HISCL) platform and detects IgG and IgM specific to SARS-CoV-2 spike and nucleocapsid proteins. Quantification accuracy and reproducibility were evaluated using serially diluted samples from 60 SARS-CoV-2-infected patients. Assay performance was evaluated using serum samples from the SARS-CoV-2-infected patients and 500 SARS-CoV-2-negative serum samples collected before the emergence of SARS-CoV-2. The system showed high quantification accuracy (range, 10
), high reproducibility (within 5%), and no cross-reaction between SARS1- and MERS-S proteins. Detection accuracy was 98.3% and 93.3% for IgG and IgM against spike proteins and 100% and 71.7% for IgG and IgM against nucleocapsid proteins, respectively. Mean antibody levels were > 10 times that in negative samples upon admission and > 100 times that at convalescent periods. Clinical severity upon admission was not correlated with IgG or IgM levels. This highly quantitative, reproducible assay system with high clinical performance may help analyze temporal serological/immunological profiles of SARS-CoV-2 infection and SARS-CoV-2 vaccine effectiveness.
Programmed cell death ligand-1 (PD-L1) has recently gained considerable attention for its role in tumor immune escape. Here, we identify a miR-197/CKS1B/STAT3-mediated PD-L1 network in chemoresistant ...non-small-cell lung cancer (NSCLC), independent of immunoinhibitory signals. miR-197 is downregulated in platinum-resistant NSCLC specimens, resulting in the promotion of chemoresistance, tumorigenicity, and pulmonary metastasis in vitro and in vivo. Mechanistic investigations reveal that a miR-197-mediated CKS1B/STAT3 axis exerts tumor progression regulated by various oncogenic genes (Bcl-2, c-Myc, and cyclin D1), and PD-L1 is a putative biomarker of this axis. Furthermore, we demonstrate that a miR-197 mimic sensitizes PD-L1high drug-resistant cells to chemotherapy. These results indicate that the biological interaction between PD-L1 and chemoresistance occurs through the microRNA regulatory cascade. More importantly, expression levels of miR-197 are inversely correlated with PD-L1 expression (n = 177; P = 0.026) and are associated with worse overall survival (P = 0.015). Our discoveries suggest that the miR-197/CKS1B/STAT3-mediated network can drive tumor PD-L1 expression as a biomarker of this cascade, and miR-197 replacement therapy may be a potential treatment strategy for chemoresistant NSCLC.
To investigate the efficacy and safety of trastuzumab deruxtecan, an antibody-drug conjugate targeting human epidermal growth factor receptor 2 (HER2) with a topoisomerase I inhibitor payload, in ...patients with uterine carcinosarcoma (UCS) expressing HER2.
Patients with recurrent UCS with HER2 immunohistochemistry scores ≥1+ previously treated with chemotherapy were included. Patients were assigned to the HER2-high (immunohistochemistry score ≥2+; n = 22) or low (immunohistochemistry score of 1+; n = 10) groups for primary and exploratory analyses, respectively. Trastuzumab deruxtecan 6.4 or 5.4 mg/kg was administered intravenously once every 3 weeks until unacceptable toxicity or disease progression. Dose modification was based on the updated recommended phase II dose for breast cancer to be 5.4 mg/kg. The primary end point was the objective response rate by central review in the HER2-high group. Secondary end points included the overall response rate (ORR) in the HER2-high group by investigator assessment, ORR in the HER2-low group, progression-free survival (PFS), overall survival (OS), and safety.
The ORR by central review in the HER2-high and HER2-low groups were 54.5% (95% CI, 32.2 to 75.6) and 70.0% (95% CI, 34.8 to 93.3) and those by investigator assessments were 68.2% and 60.0%, respectively. The median PFS and OS in the HER2-high and HER2-low groups were 6.2 and 13.3 months and 6.7 months and not reached, respectively. Grade ≥ 3 adverse events occurred in 20 patients (61%). Grades 1-2 and 3 pneumonitis/interstitial lung disease occurred in eight (24%) and one (3%) patient, respectively.
Trastuzumab deruxtecan has efficacy in patients with UCS, regardless of HER2 status. The safety profile was generally consistent with that previously reported. Toxicities were manageable with appropriate monitoring and treatment.
Epidermal growth factor receptor (EGFR) exon 20 insertion mutations (Exon20ins) account for 4-12% of all EGFR mutations in non-small cell lung cancer (NSCLC) patients. Data on the differences in ...clinical characteristics between patients with Exon20ins and major mutations (M-mut) such as exon 19 deletion and L858R are limited. We retrospectively reviewed advanced NSCLC patients with EGFR mutations, who were treated with systemic therapy between January 2011 and December 2019. We identified 23 patients with Exon20ins and 534 patients with M-mut. In Exon20ins patients, the median age was 60 (range 27-88) years, and females and never-smokers were predominant. Clinical characteristics were similar in the two groups. In Exon20ins patients, 17 patients received platinum doublet as first-line therapy, and the overall response rate (ORR) and median progression-free survival (mPFS) were 11.8% and 8.9 months. Additionally, seven patients received conventional EGFR-tyrosine kinase inhibitors (TKIs), and eight patients anti-PD-1 antibodies in any-line therapy. ORR and mPFS of EGFR-TKIs and anti-PD-1 antibodies were 0%, 2.2 months and 25%, 3.1 months, respectively. Overall survival was significantly shorter in Exon20ins patients than in M-mut patients (29.3 vs. 43.4 months, p = 0.04). The clinical outcomes in Exon20ins patients were not satisfactory compared to M-mut patients.
Chaperone‐mediated autophagy (CMA) is a lysosomal degradation pathway of selective soluble proteins. Lysosome‐associated membrane protein type 2a (LAMP2A) is the key receptor protein of CMA; ...downregulation of LAMP2A leads to CMA blockade. Although CMA activation has been involved in cancer growth, CMA status and functions in non–small cell lung cancer (NSCLC) by focusing on the roles in regulating chemosensitivity remain to be clarified. In this study, we found that LAMP2A expression is elevated in NSCLC cell lines and patient's tumors, conferring poor survival and platinum resistance in NSCLC patients. LAMP2A knockdown in NSCLC cells suppressed cell proliferation and colony formation and increased the sensitivity to chemotherapeutic drugs in vitro. Furthermore, we found that intrinsic apoptosis signaling is the mechanism of cell death involved with CMA blockade. Remarkably, LAMP2A knockdown repressed tumorigenicity and sensitized the tumors to cisplatin treatment in NSCLC‐bearing mice. Our discoveries suggest that LAMP2A is involved in the regulation of cancer malignant phenotypes and represents a promising new target against chemoresistant NSCLC.
Lysosome‐associated membrane protein type 2a (LAMP2A) is the key receptor protein of chaperone‐mediated autophagy (CMA). Downregulation of LAMP2A leads to CMA blockade. Our discoveries suggest that LAMP2A is involved in the regulation of cancer malignant phenotypes through CMA modulation and represents a promising new target against chemoresistant non–small cell lung cancer (NSCLC).
The use of patient‐derived xenografts (PDXs) has recently attracted attention as a drug discovery platform with a high predictive clinical efficacy and a preserved tumor heterogeneity. Given the ...racial differences in genetic variations, it would be desirable to establish a PDX library from Japanese cancer patients on a large scale. We thus tried to construct the Japanese PDX (J‐PDX) library with a detailed clinical information for further clinical utilization. Between August 2018 and May 2020, a total of 1126 cancer specimens from 1079 patients were obtained at the National Cancer Center Hospital and National Cancer Center Hospital East, Japan, and were immediately transplanted to immunodeficient mice at the National Cancer Center Research Institute. A total of 298 cross‐cancer PDXs were successfully established. The time to engraftment varied greatly by cancer subtypes, especially in the first passage. The engraftment rate was strongly affected by the clinical stage and survival time of the original patients. Approximately 1 year was needed from tumor collection to the time when coclinical trials were conducted to test the clinical utility. The 1‐year survival rates of the patients who were involved in establishing the PDX differed significantly, from 95.6% for colorectal cancer to 56.3% for lung cancer. The J‐PDX library consisting of a wide range of cancer subtypes has been successfully established as a platform for drug discovery and development in Japan. When conducting coclinical trials, it is necessary to consider the target cancer type, stage, and engraftment rate in light of this report.
We have successfully established a PDX library derived from Japanese cancer patients. In less than 2 years, we have registered more than 1000 specimens and established nearly 300 PDXs. We will further enrich the library and use it as a platform to accelerate drug discovery in Japan.
Background
Cancer cachexia is a multifactorial syndrome characterized by weight loss leading to immune dysfunction that is commonly observed in patients with advanced non-small cell lung cancer ...(NSCLC). We examined the impact of cachexia on the prognosis of patients with advanced NSCLC receiving pembrolizumab and evaluated whether the pathogenesis of cancer cachexia affects the clinical outcome.
Patients and methods
Consecutive patients with advanced NSCLC treated with pembrolizumab were retrospectively enrolled in the study. Serum levels of pro-inflammatory cytokines and appetite-related hormones, which are related to the pathogenesis of cancer cachexia, were analyzed. Cancer cachexia was defined as (1) a body weight loss > 5% over the past 6 months, or (2) a body weight loss > 2% in patients with a body mass index < 20 kg/m
2
.
Results
A total of 133 patients were enrolled. Patients with cachexia accounted for 35.3%. No significant difference in the objective response rate was seen between the cachexia and non-cachexia group (29.8% vs. 34.9%,
P
= 0.550), but the median progression-free survival (PFS) and overall survival (OS) periods were significantly shorter in the cachexia group than in the non-cachexia group (PFS: 4.2 months vs. 7.1 months,
P
= 0.04, and OS: 10.0 months vs. 26.6 months,
P
= 0.03). The serum TNF-alpha, IL-1 alpha, IL-8, IL-10, and leptin levels were significantly associated with the presence of cachexia, but not with the PFS or OS.
Conclusion
The presence of cachexia was significantly associated with poor prognosis in advanced NSCLC patients receiving pembrolizumab, not with the response to pembrolizumab.
We assessed the intratumor pharmacokinetics of fam- trastuzumab deruxtecan, T-DXd (known as DS-8201a), a novel HER2-targeted antibody-drug conjugate, using phosphor-integrated dots (PID)-imaging ...analysis to elucidate its pharmacologic mechanism.
We used two mouse xenograft models administered T-DXd at the concentration of 4 mg/kg: (i) a heterogeneous model in which HER2-positive and HER2-negative cell lines were mixed, and (ii) a homogeneous model in which both cell types were transplanted separately into the same mouse. PID imaging involved immunostaining using novel high-intensity fluorescent nanoparticles. The distribution of T-DXd was assessed by PID imaging targeting the parent antibody, trastuzumab, and the payload, DXd, in serial frozen sections, respectively.
After T-DXd administration in the heterogeneous model, HER2 expression tended to decrease in a time-dependent manner. The distribution of trastuzumab and DXd was observed by PID imaging along the HER2-positive area throughout the observation period. A detailed comparison of the PID distribution between trastuzumab and DXd showed that trastuzumab matched almost perfectly with the HER2-positive area. In contrast, DXd exhibited widespread distribution in the surrounding HER2-negative area as well. In the HER2-negative tumor of the homogeneous model, the PID distribution of trastuzumab and DXd remained extremely low throughout the observation period.
Our results suggest that T-DXd is distributed to tumor tissues via trastuzumab in a HER2-dependent manner and then to adjacent HER2-negative areas. We successfully visualized the intratumor distribution of T-DXd and its mechanism of action, the so-called "bystander effect."
Liquid biopsy analyzes the current status of primary tumors and their metastatic regions. We aimed to develop an optimized protocol for single‐cell sequencing of floating tumor cells (FTCs) in ...pleural effusion as a laboratory test. FTCs were enriched using a negative selection of white blood cells by a magnetic‐activated cell sorting system, and CD45‐negative and cytokeratin‐positive selection using a microfluidic cell separation system with a dielectrophoretic array. The enriched tumor cells were subjected to whole‐genome amplification (WGA) followed by genome sequencing. The FTC analysis detected an EGFR exon 19 deletion in Case 1 (12/19 cells, 63.2%), and EML4‐ALK fusion (17/20 cells, 85%) with an alectinib‐resistant mutation of ALK (p.G1202R) in Case 2. To eliminate WGA‐associated errors and increase the uniformity of the WGA product, the protocol was revised to sequence multiple single FTCs individually. An analytical pipeline, accurate single‐cell mutation detector (ASMD), was developed to identify somatic mutations of FTCs. The large numbers of WGA‐associated errors were cleaned up, and the somatic mutations detected in FTCs by ASMD were concordant with those found in tissue specimens. This protocol is applicable to circulating tumor cells analysis of peripheral blood and expands the possibility of utilizing molecular profiling of cancers.
An optimized protocol is established for single‐cell sequencing of floating tumor cells (FTCs) in pleural effusion as a laboratory test that could be utilized for patient care. The FTC analysis detected an EGFR exon 19 deletion in Case 1 (12/19 cells, 63.2%) and EML4‐ALK fusion in Case 2 (17/20 cells, 85%). A novel analytical pipeline, accurate single‐cell mutation detector (ASMD), was developed to identify somatic mutations in single cells accurately.
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