Abstract PS2-17: Identification of cell-free microRNA signatures in pre-operative plasma from breast cancer patients

Background: Breast cancer (BC) is a heterogeneous disease and difficult to treat once metastasis occurs. Thus, determining blood molecular biomarkers that allow for early diagnosis would help to identify BC patients at higher risk. MicroRNAs (miRs) are short sequences (18-22 base pairs) and promising candidates as biomarkers due to their high stability in blood. Using a direct blood cell-free miR (cfmiR) next generation sequencing (NGS) -based assay that requires no extraction, we assessed 2083 cfmiRs in plasma samples from BC patients. We hypothesize that specific cfmiR signatures detected in plasma from BC patients are associated with early BC diagnosis. Those cfmiRs represent unique patterns that may allow for monitoring BC tumor burden and early detection.Methods: Two cohorts of pre-operative plasma samples from BC patients (n= 158), one cohort of pre-operative plasma samples from patients with BC brain metastasis (BCBM, n= 5), and a cohort of female normal donors’ plasma samples (n=20) were assessed by HTG EdgeSeq miR whole transcriptome assay. All primary BC tumors were histopathology staged (TNM, AJCC 8th) after surgery and divided into two different cohorts: the BC-1 cohort (n= 80, including stage I= 39, II= 37, and III= 4 patients), and the BC-2 cohort (n= 78, including stage I= 42, II= 33, and III= 3 patients). All of the samples were analyzed using DESeq2 normalization and interrogated for differentially expressed (DE) miRs using a cut-off of 30 counts, FC>1.2 or <-1.2, and FDR (p<0.05). We utilized the BC-1 group as the training cohort and the BC-2 and the BCBM cohorts were used to validate the observations in BC-1.

Results: In a retrospective study the cfmiR profiles obtained from BC-1 patients were compared to the cfmiR profiles obtained from normal donors’ plasma samples. Briefly, 328 cfmiRs were DE in plasma samples from the BC-1 cohort compared to normal donors’ plasma samples, of which 184 were upregulated and 144 were downregulated. To validate our findings, we screened the plasma samples from the BC-2 cohort (n=78). The results showed that 181 of 361 DE cfmiRs were downregulated and 180 were upregulated. By comparing both BC cohorts we found 269 DE cfmiRs consistently changing, which included 82% and 74.5% of the cfmiRs identified in BC-1 and BC-2 cohorts, respectively. In addition, we compared the cfmiR expression of BCBM (n=5) and normal donors’ plasma samples. Of the 300 DE cfmiRs, 30 were downregulated and 270 were upregulated. By integrative analysis, a 59 cfmiR signature observed in BCBM plasma samples was consistently identified in both BC-1 and BC-2 cohorts. Also, 172 cfmiRs were found exclusively in BCBM and not in primary BC tumors. Receiving operative characteristic curve analysis showed that the 59 cfmiR signature was able to distinguish primary BC from female normal donors’ (BC-1 AUC= 0.910, p<0.05 and BC-2 AUC= 0.922, p<0.05, respectively). Using the 59 cfmiR signature, the first five components of the principal component analysis showed 85.26% and 85.27% mean cumulative variance for BC-1 and BC-2 respectively.Conclusions: Specific cfmiR patterns were associated with primary BC tumors and may have potential utility for early BC diagnosis, including disease recurrence. A 59 cfmiR signature detected in primary BC patients was able to detect BCBM and may have potential clinical utility in monitoring patients at higher risk of metastasis. Further analysis are in progress to validate our observations.

Citation Format: Matias Alberto Bustos, Negin Rahimzadeh, Xiaoqing Zhang, Kevin D. Tran, Grace Chang, Carol Nishikubo, Dave S.B. Hoon. Identification of cell-free microRNA signatures in pre-operative plasma from breast cancer patients [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-17.

Assessment of Cell-Free microRNA by NGS Whole-Transcriptome Analysis in Cutaneous Melanoma Patients' Blood

MicroRNAs (miRs) are small RNA molecules (18-22 nucleotides) that regulate the transcriptome at a post-transcriptional level by affecting the expression of specific genes. This regulatory mechanism is critical to maintain cell homeostasis and specific functions. Aberrant expression of miRs have been associated with pathobiological processes including cancer. There are few technologies available that are able to profile whole-genome miR expression using minimal amounts of blood samples and without the need for time-consuming extraction steps. Here, we describe the HTG EdgeSeq miR Whole-Transcriptome Assay (WTA) in serum and plasma samples. To identify specific cell-free miR (cfmiR) patterns we have first focused on the analysis of normal donor samples and have then compared these to patients with cutaneous melanoma. The identification of specific cfmiR for melanoma patients will allow for better patient surveillance during targeted and/or checkpoint inhibitor immunotherapy (CII) treatment.

A Pilot Study Comparing the Efficacy of Lactate Dehydrogenase Levels Versus Circulating Cell-Free microRNAs in Monitoring Responses to Checkpoint Inhibitor Immunotherapy in Metastatic Melanoma Patients

Simple Summary

Improvement in melanoma patients with metastatic disease is needed to better assess immunotherapies. Lactate dehydrogenase (LDH) is currently an accepted biomarker for stage IV, but it has limited utility for stage III melanoma patients. Thus, finding biomarkers for metastatic melanoma is important not only to identify progressive melanoma tumors, but also to monitor patients under checkpoint inhibitor immunotherapy (CII). The aim of this pilot study was to demonstrate the utility of circulating cell-free microRNAs (cfmiRs) as potential blood biomarkers for stage III and IV melanoma patients compared to LDH. To accomplish this aim, we profiled for cfmiR the plasma of metastatic melanoma patients before and during CII treatment, and compared them to normal healthy donors’ samples. The cfmiR profiling was performed using an NGS-based miRNA assay, which requires no extraction and a small volume input. We found specific cfmiR signatures in stage III and IV metastatic melanoma patients. As a proof of concept, our results showed that certain cfmiRs are associated with CII outcomes.

Abstract

Serum lactate dehydrogenase (LDH) is a standard prognostic biomarker for stage IV melanoma patients. Often, LDH levels do not provide real-time information about the metastatic melanoma patients’ disease status and treatment response. Therefore, there is a need to find reliable blood biomarkers for improved monitoring of metastatic melanoma patients who are undergoing checkpoint inhibitor immunotherapy (CII). The objective in this prospective pilot study was to discover circulating cell-free microRNA (cfmiR) signatures in the plasma that could assess melanoma patients’ responses during CII. The cfmiRs were evaluated by the next-generation sequencing (NGS) HTG EdgeSeq microRNA (miR) Whole Transcriptome Assay (WTA; 2083 miRs) in 158 plasma samples obtained before and during the course of CII from 47 AJCC stage III/IV melanoma patients’ and 73 normal donors’ plasma samples. Initially, cfmiR profiles for pre- and post-treatment plasma samples of stage IV non-responder melanoma patients were compared to normal donors’ plasma samples. Using machine learning, we identified a 9 cfmiR signature that was associated with stage IV melanoma patients being non-responsive to CII. These cfmiRs were compared in pre- and post-treatment plasma samples from stage IV melanoma patients that showed good responses. Circulating miR-4649-3p, miR-615-3p, and miR-1234-3p demonstrated potential prognostic utility in assessing CII responses. Compared to LDH levels during CII, circulating miR-615-3p levels were consistently more efficient in detecting melanoma patients undergoing CII who developed progressive disease. By combining stage III/IV patients, 92 and 17 differentially expressed cfmiRs were identified in pre-treatment plasma samples from responder and non-responder patients, respectively. In conclusion, this pilot study demonstrated cfmiRs that identified treatment responses and could allow for real-time monitoring of patients receiving CII.

Integrated Assessment of Circulating Cell-Free MicroRNA Signatures in Plasma of Patients with Melanoma Brain Metastasis

Primary cutaneous melanoma frequently metastasizes to distant organs including the brain. Identification of cell-free microRNAs (cfmiRs) found in the blood can be used as potential body fluid biomarkers for detecting and monitoring patients with melanoma brain metastasis (MBM). In this pilot study, we initially aimed to identify cfmiRs in the blood of MBM patients. Normal donors plasma (healthy, n = 48) and pre-operative MBM patients' plasma samples (n = 36) were compared for differences in >2000 microRNAs (miRs) using a next generation sequencing (NGS) probe-based assay. A 74 cfmiR signature was identified in an initial cohort of MBM plasma samples and then verified in a second cohort of MBM plasma samples (n = 24). Of these, only 58 cfmiRs were also detected in MBM tissues (n = 24). CfmiR signatures were also found in patients who have lung and breast cancer brain metastasis (n = 13) and glioblastomas (n = 36) compared to MBM plasma samples. The 74 cfmiR signature and the latter cfmiR signatures were then compared. We found a 6 cfmiR signature that was commonly upregulated in MBM plasma samples in all of the comparisons, and a 29 cfmiR signature that distinguishes MBM patients from normal donors' samples. In addition, we assessed for cfmiRs in plasma (n = 20) and urine (n = 14) samples collected from metastatic melanoma patients receiving checkpoint inhibitor immunotherapy (CII). Pre- and post-treatment samples showed consistent changes in cfmiRs. Analysis of pre- and post-treatment plasma samples showed 8 differentially expressed (DE) cfmiRs that overlapped with the 35 cfmiR signature found in MBM patients. In paired pre-treatment plasma and urine samples receiving CII 8 cfmiRs overlapped. This study identified specific cfmiRs in MBM plasma samples that may potentially allow for assessment of melanoma patients developing MBM. The cfmiR signatures identified in both blood and urine may have potential utility to assess CII responses after further validation.

Methotrexate in the treatment of pemphigus vulgaris: experience in 23 patients

BACKGROUND

The standard treatment for patients with pemphigus vulgaris has long consisted of high-dose glucocorticoids. Studies regarding the use of methotrexate in pemphigus vulgaris date back to 1968, but few have quantitatively described a steroid-sparing effect conferred by methotrexate.

OBJECTIVES

We sought to evaluate the efficacy of methotrexate in 23 patients with pemphigus vulgaris, using the drug's steroid-sparing effect as the primary indicator of clinical improvement. We investigated whether methotrexate could be used as monotherapy in some patients.

METHODS

Retrospective chart review was used to analyse the records of patients with pemphigus vulgaris treated with methotrexate at the New York University Langone Medical Center for at least three consecutive months between 2000 and 2012. Diagnosis was made by tissue biopsy and either direct or indirect immunofluorescence tests and enzyme-linked immunosorbent assay.

RESULTS

Improvement in clinical symptoms was observed in 91% of patients. Sixteen patients (70%) were eventually weaned completely off prednisone, with a mean time to discontinuation of 18 months. In total 23% of patients enjoyed a partial steroid-sparing effect, requiring a mean maintenance dose of prednisone of 6·75 mg daily. Two patients (9%) developed possible adverse events requiring cessation of the drug, and one patient received no therapeutic benefit from the drug.

CONCLUSIONS

Methotrexate is a useful and well-tolerated therapy with considerable steroid-sparing effect in patients with pemphigus vulgaris. It may be considered a first-line adjuvant therapy in the treatment of this difficult disease.

Interaction between dextromethorphan and norpethidine in rats

With increasing interest in the application of dextromethorphan in pain control, it is probable that patients will receive this drug in combination with analgesics such as opioids, giving rise to the potential for previously unobserved drug interactions. The interaction between dextromethorphan, and its pharmacologically active metabolite dextrorphan, and norpethidine, a toxic metabolite of pethidine, was examined in rats. Rats were assigned to receive dextromethorphan (0, 20 or 40 mg/kg) or dextrorphan (0, 15 or 30 mg/kg) combined with norpethidine (0, 28 or 42 mg/kg). The occurrence of seizures, myoclonic jerks and shivering was recorded for 60 min after drug administration. Norpethidine produced dose-related increases in the incidence of seizures, myoclonic jerks and shivering. Dextromethorphan, but not dextrorphan, increased the incidence of these behaviours. It is recommended that extreme caution be exercised if dextromethorphan and pethidine are to be used together.

Reduced Purkinje cell size in the cerebellar vermis of elderly patients with schizophrenia

OBJECTIVE

The authors' goal was to compare the size and linear density of Purkinje cells in the cerebellar vermis of subjects with and without schizophrenia.

METHOD

Blocks of alcohol-fixed cerebellar vermis were dissected at autopsy from the brains of 14 elderly patients with schizophrenia and 13 elderly subjects with no history of neuropsychiatric illness. The blocks of vermis were sectioned and stained with 1% cresyl violet. The linear density and cross-sectional area of Purkinje cells were measured by using computer-assisted image analysis. The subjects with schizophrenia had been assessed with clinical rating scales within 1 year prior to death.

RESULTS

The average cross-sectional areas of Purkinje cells of the patients with schizophrenia were significantly smaller (by 8.3%) than those of the subjects without neuropsychiatric illness. No difference in Purkinje cell linear density was observed between the two groups. Significant correlations were seen between Purkinje cell size and scores on the Mini-Mental State, the Brief Psychiatric Rating Scale, and the antipsychotic drug dose.

CONCLUSIONS

These data indicate cerebellar involvement in schizophrenia; they are also consistent with reports of reduced neuronal size in other brain regions of patients with schizophrenia. These findings support a model of wide-spread central nervous system abnormality in schizophrenia.

The pharmacokinetics of a single dose of artemisinin in subjects with liver cirrhosis. Bach Mai-Amsterdam Research Group on Artemisinin

Artemisinin is mainly eliminated by hepatic transformation. To investigate whether the clearance of artemisinin in patients with liver cirrhosis is different from healthy volunteers, a pharmacokinetic study was performed in male Vietnamese patients with Child B cirrhosis of the liver who received 500 mg of artemisinin orally. The results were compared to those found in a previous study in healthy subjects. The mean (+/- SD) area under the concentration time curve was 2365 (+/- 1761) h ng/ml; the mean (+/- SD) clearance, 382 (+/- 303)L/h. The elimination half life was 4 (+/- 1.3) h extimated by log-linear regression and 2.4 +/- 0.9 h estimated by non-linear regression using a one-compartment first order elimination model. The mean (+/- SD) absorption time was 1.55 (+/- 0.8) h. These results were not different from the results of healthy subjects and show that liver disease has no effect on the availability and clearance of oral artemisinin, indicating that artemisinin has an intermediate hepatic extraction ratio and that there is no significant first pass effect.

The pharmacokinetics of a single dose of artemisinin in patients with uncomplicated falciparum malaria

The pharmacokinetics of artemisinin was studied in 11 Vietnamese patients with uncomplicated falciparum malaria after a single 500 mg oral dose. Curative treatment with mefloquine (15 mg/kg) was provided 24 hr after the artemisinin dose. Artemisinin concentrations were measured by high-performance liquid chromatography with electrochemical detection. The following pharmacokinetic results were found (all mean +/- SD); calculated volume of distribution/bioavailability = 22.8 +/- 16.6 L.kg-1, mean absorption time = 1.16 +/- 0.92 hr, calculated maximum concentration = 364 +/- 250 micrograms.L-1 occurring at 2.88 +/- 1.71 hr after drug intake, and an elimination half-life of 2.72 +/- 1.76 hr. Bioavailability was low. These results do not differ from results in healthy subjects. Parasites disappeared rapidly, with a mean parasite clearance time of 36 hr. No relationship was found between pharmacokinetics and the parasite elimination rate. Tolerance to the single dose of artemisinin was good. No adverse effects were detected. In conclusion, pharmacokinetics of a single dose of artemisinin for uncomplicated falciparum malaria is not different from findings in healthy subjects. A single dose of 500 mg of artemisinin is effective in reducing parasitemia in nonsevere lalciparum malaria and is well-tolerated.