Molecular features of gastroenteropancreatic neuroendocrine carcinoma: A comparative analysis with lung neuroendocrine carcinoma and digestive adenocarcinomas

Objective: There is an ongoing debate about whether the management of gastroenteropancreatic(GEP)neuroendocrine carcinoma(NEC) should follow the guidelines of small-cell lung cancer(SCLC). We aim to identify the genetic differences of GEPNEC and its counterpart.Methods: We recruited GEPNEC patients as the main cohort, with lung NEC and digestive adenocarcinomas as comparative cohorts. All patients undergone next-generation sequencing(NGS). Different gene alterations were compared and analyzed between GEPNEC and lung NEC(LNEC), GEPNEC and adenocarcinoma to yield the remarkable genes.Results: We recruited 257 patients, including 99 GEPNEC, 57 LNEC, and 101 digestive adenocarcinomas.Among the mutations, KRAS, RB1, TERT, IL7R, and CTNNB1 were found to have different gene alterations between GEPNEC and LNEC samples. Specific genes for each site were revealed: gastric NEC(TERT amplification),colorectal NEC(KRAS mutation), and bile tract NEC(ARID1A mutation). The gene disparities between small-cell NEC(SCNEC) and large-cell NEC(LCNEC) were KEAP1 and CDH1. Digestive adenocarcinoma was also compared with GEPNEC and suggested RB1, APC, and KRAS as significant genes. The TP53/RB1 mutation pattern was associated with first-line effectiveness. Putative targetable genes and biomarkers in GEPNEC were identified in22.2% of the patients, and they had longer progression-free survival(PFS) upon targetable treatment [12.5 months vs. 3.0 months, HR=0.40(0.21-0.75), P=0.006].Conclusions: This work demonstrated striking gene distinctions in GEPNEC compared with LNEC and adenocarcinoma and their clinical utility.

Analysis of Vibrational Performance of A Piezoelectric Micropump with Diffuse/Nozzle Microchannel

Piezoelectric transducers of different external diameters are designed and fabricated and incorporated into micropumps. Through finite element analysis, it is shown that the volume efficiency of the micropump reaches its maximum value for the first mode of vibration. The variation of maximum displacement with frequency is determined under free and forced vibration. Results demonstrate that this variation shows the same trend for different driving waves at the same driving voltage. The maximum displacement under forced vibration is less than that under free vibration. The displacement increases with decreasing distance from the center of the transducer. The maximum displacement is inversely proportional to the diameter of the transducer and proportional to the driving voltage under both free and forced vibrations. Finally, the micropump flow rate and pressure are measured and are found to manifest the same trend as the maximum displacement under the same driving conditions. For a piezoelectric transducer of 12 mm external diameter, the maximum flow rate and pressure value are 150 μL/min and 346 Pa, respectively, under sine-wave driving at 100 Vpp driving voltage.

Clinical spectrum and prognostic value of TP53 mutations in circulating tumor DNA from breast cancer patients in China

Background:TP53 mutations are common in breast cancer.There is currently no large-scale cohort study to investigate the TP53 landscape in breast cancer patients from China.The predictive value of TP53 mutations for the efficacy of human epidermal growth factor receptor 2(HER2)-targeted therapy in breast cancer remains controversial.In the present study,we aimed to analyze the clinical spectrum and prognostic value of TP53 mutations in circulating tumor DNA(ctDNA)from breast cancer patients in China.Methods:We retrospectively analyzed the clinical data and TP53 mutation features in ctDNA samples from 804 patients withmetastatic breast cancer.TP53 mutations were detected by target region capture-based next-generation sequencing.The relationship between TP53 mutation status and disease-free survival(DFS)was analyzed in 444 patientswithmetastatic breast cancer.Moreover,the relationship between TP53 mutation status and progression-free survival(PFS)was analyzed in 55 HER2-positive patients treated with first-line trastuzumab-based therapy.Kaplan-Meier analysis was performed to estimate the survival curves of the different subgroups,and the log-rank test was used to compare the curves.A Cox regression model was used to estimate multivariable-adjusted hazard ratios and their 95%confidence intervals(CIs)associated with the DFS and PFS.Results:Among the 804 investigated patients,431(53.6%)patients harbored TP53 mutations.TP53 mutations were differentially distributed among different molecular subtypes of breast cancer(P<0.05).Patients with TP53 mutations had a shorter DFS than those with wild-type TP53(hazard ratio=1.32,95%CI=1.09-1.61,P=0.005).TP53 mutations in exons 5-8 were associated with worse outcome(hazard ratio=1.50,95%CI=1.11-2.03,P=0.009).However,TP53 mutation status was not significantly associated with PFS in HER2-positive patients who received firstline trastuzumab-based therapy(P=0.966).Interestingly,in the taxane combination group,patients with TP53 mutations exhibited longer PFS than those without TP53 mutations(hazard ratio=0.08,95%CI=0.02-0.30,P<0.001).However,in the nontaxane combination group,patients with TP53 mutations displayed shorter PFS than those with wild-type TP53(hazard ratio=4.84,95%CI=1.60-14.66,P=0.005).Conclusions:TP53 mutations in exons 5-8 may be an independent prognostic marker for short DFS in patients with metastatic breast cancer.TP53 mutations had opposite effects on trastuzumab-treated patients treated with and without taxanes.

Detection and extraction of heavy metal ions using paper-based analytical devices fabricated via atom stamp printing

As a promising concept,microfluidic paper-based analytical devices(μPADs)have seen rapid development in recent years.In this study,a new method of fabricatingμPADs by atom stamp printing(ASP)is proposed and studied.The advantages of this new method compared to other methods include its low cost,ease of operation,high production efficiency,and high resolution(the minimum widths of the hydrophilic channels and hydrophobic barriers are 328 and 312μm,respectively).As a proof of concept,μPADs fabricated with the ASP method were used to detect different concentrations of Cu^(2+)via a colorimetric method.Moreover,combined with a distance-based detection method,these devices achieved a Cu^(2+)detection limit of down to 1mg/L.In addition,a new paper-based solid–liquid extraction device(PSED)based on a three-dimensional(3D)μPAD with a“3+2”structure and a recyclable extraction mode was developed.Specifically,using the characteristics of paper filtration and capillary force,the device completed multiple extraction and filtration steps from traditional solid–liquid extraction processes with high efficiency.The developed PSED platform allows the detection of heavy metal ions much more cheaply and simply and with a faster response time at the point of care,and it has great promise for applications in food safety and environmental pollution in resource-limited areas.

Mutational characteristics determined using circulating tumor DNA analysis in triple-negative breast cancer patients with distant metastasis

Dear editor,Breast cancer has been considered as the most common malignancy and the leading cause of death in women worldwide[1].Triple-negative breast cancer(TNBC)accounts for 10%-20%of breast cancers,which are characterized by the absence of estrogen receptor(ER),progesterone receptor(PR),and amplification of human epidermal growth factor receptor 2(HER2)[2].TNBC is well known for its rapid progressiveness,high rate of distant organ recurrence,and poor prognosis.Metastasis remains the major cause of death for patients with TNBCs.Up to date,the only direct treatment for metastatic TNBCs is chemotherapy,which has been challenged by tumor heterogeneity and drug resistance.Lack of effective targeted therapy for metastatic TNBCs impels researchers to focus on discovering potentially actionable targets through mutational profiling.

The molecular tumor burden index as a response evaluation criterion in breast cancer

Circulating tumor DNA(ctDNA)is a potential biomarker of prognosis and therapeutic response.We conducted this study to explore the role of the molecular tumor burden index(mTBI)in ctDNA as a therapeutic response and prognostic biomarker in a larger cohort prospective phase III randomized multicenter study.We collected 291 plasma samples from 125 metastatic breast cancer patients from the CAMELLIA study(NCT01917279).Target-capture deep sequencing of 1021 genes was performed to detect somatic variants in ctDNA from the plasma samples.The pretreatment mTBI value was correlated with tumor burden(P=0.025).Patients with high-level pretreatment mTBI had shorter overall survival than patients with low-level pretreatment mTBI,and the median overall survival was 40.9 months and 68.4 months,respectively(P=0.011).Patients with mTBI decrease to less than 0.02%at the first tumor evaluation had longer progression-free survival and overall survival(P<0.001 and P=0.007,respectively).The mTBI has good sensitivity to identify complete response/partial response and progressive disease based on computed tomography scans(88.5%and 87.5%,respectively).The patients classified as molecular responders had longer progression-free survival and overall survival than the nonmolecular responders in the overall cohort(P<0.001 and P=0.036,respectively),as well as in the cohort in which computed tomography scans were defined as representing stable disease(P=0.027 and P=0.015,respectively).The mTBI in ctDNA detected in liquid biopsies is a potential biomarker of therapeutic response and prognosis in patients with metastatic breast cancer.

Preferable background filtering for next-generation sequencing analysis in non-small cell lung cancer:pericarcinomatous tissues or peripheral blood lymphocytes?

Dear editor,Lung cancer is the leading cause of cancer-related death worldwide,with the predominant pathological type being non-small cell lung cancer(NSCLC)[1,2].Next-gener-ation sequencing(NGS)analysis is increasingly used to help clinicians select appropriate target therapies,such as epidermal growth factor receptor-tyrosine kinase inhibitors(EGFR-TKIs)for EGFR-mutant patients[3].Both pericarcinomatous tissues and peripheral blood lymphocytes are widely used as normal control for NGS analysis.However,whether pericarcinomatous tissue is suitable for background filtering in mutation analysis remains controversial.According to the whole-genome sequencing data from The Cancer Genome Atlas(TCGA)database,there were some genomic variations in peri-carcinomatous tissue from NSCLC patients,but no driver gene mutation was detected[4,5].Therefore,deep sequencing of pericarcinomatous and tumor tissues is necessary to confirm whether pericarcinomatous tissue harbors low-frequency mutations.