Optimizing the Detection of Circulating Markers to Aid in Early Lung Cancer Detection

Distance-based paper/PMMA integrated ELISA-chip for quantitative detection of immunoglobulin G

The enzyme-linked immunosorbent assay (ELISA) is one of the most commonly implemented clinical diagnostic tools for the detection and quantification of protein biomarkers. However, conventional ELISA tests require sophisticated infrastructure, expensive reagents, long assay time, and expertise for operation, which are not often easily accessible in resource-limited settings. Microfluidic ELISA-chip based point-of-care (POC) testing allows miniaturization and integration of complex functions that facilitate their usage in limited-resource settings. The current work demonstrates a simple, portable, low cost and equipment-free paper/poly(methyl methacrylate) (PMMA) integrated microfluidic ELISA-chip as a POC device with a visual distance-based readout for quantitative detection of clinical biomarkers. The integrated paper/PMMA ELISA-chip utilizes the movement of immunoassay complexes with magnetic beads by a permanent magnet in a PMMA part of the compartment. The target concentration is translated into a visual distance signal readout for quantitative detection of biomarkers in a μPAD. Because it does not require sophisticated instruments and has the added advantages of low cost, easy operation, and disposability with quantitative visual readout, the paper/PMMA ELISA-chip holds great promise for portable detection of target bioanalytes as a POC diagnostic tool in resource-limited setups.

Ex vivo culture of circulating tumour cells derived from non-small cell lung cancer

Background

Tumour tissue-based information is limited. Liquid biopsy can provide valuable real-time information through circulating tumour cells (CTCs). Profiling and expanding CTCs may provide avenues to study transient metastatic disease.

Methods

Seventy non-small cell lung cancer (NSCLC) patients were recruited. CTCs were enriched using the spiral microfluidic chip and a RosetteSep™ using bloods from NSCLC patients. CTC cultures were carried out using the Clevers media under hypoxic conditions. CTCs were characterized using immunofluorescence and mutation-specific antibodies for samples with known mutation profiles. Exome sequencing was used to characterized CTC cultures.

Results

CTCs (>2 cells) were detected in 38/70 (54.3%) of patients ranging from 0 to 385 CTCs per 7.5 mL blood. In 4/5 patients where primary tumours harboured an EGFR exon 19 deletion, this EGFR mutation was also captured in CTCs. ALK translocation was confirmed on CTCs from a patient harbouring an ALK-rearrangement in the primary tumour. Short term CTC cultures were successfully generated in 9/70 NSCLC patients. Whole exome sequencing (WES) confirmed the presence of somatic mutations in the CTC cultures with mutational signatures consistent with NSCLC.

Conclusions

We were able to detect CTCs in >50% of NSCLC patients. NSCLC patients with >2 CTCs had a poor prognosis. The short-term CTC culture success rate was 12.9%. Further optimization of this culture methodology may provide a means by which to expand CTCs derived from NSCLC patient’s bloods. CTC cultures allow for expansion of cells to a critical mass, allowing for functional characterization of CTCs with the goal of drug sensitivity testing and the creation of CTC cell lines.

Protein glycosylation in head and neck cancers: From diagnosis to treatment

Glycosylation is the most common post-translational modification (PTM) of proteins. Malignant tumour cells frequently undergo an alteration in surface protein glycosylation. This phenomenon is also common in cancers of the head and neck, most of which are squamous cell carcinomas (HNSCC). It affects cell functions, including proliferation, motility and invasiveness, thus increasing the propensity to metastasise. HNSCC represents the sixth most frequent malignancy worldwide. These neoplasms, which arise from the mucous membranes of the various anatomical subsites of the upper aero-digestive tract, are heterogeneous in terms of aetiology and clinico-pathologic features. With current treatments, only about 50% of HNSCC patients survive beyond 5-years. Therefore, there is the pressing need to dissect NHSCC heterogeneity to inform treatment choices. In particular, reliable biomarkers of predictive and prognostic value are eagerly needed. This review describes the current state of the art and bio-pathological meaning of glycosylation signatures associated with HNSCC and explores the possible role of tumour specific glycoproteins as potential biomarkers and attractive therapeutic targets. We have also compiled data relating to altered glycosylation and the nature of glycoproteins as tools for the identification of circulating tumour cells (CTCs) in the new era of liquid biopsy.

Sputum Cell-Free DNA: Valued Surrogate Sample for Detection of EGFR Mutation in Patients with Advanced Lung Adenocarcinoma

Sputum is a common cytologic sample type, but its potential use in EGFR mutation detection in patients with lung cancer is not fully evaluated. This study established an improved sputum cell-free DNA (cfDNA) extraction method study and applied a super-amplification refractory mutation system to detect the EGFR mutation status in sputum cfDNA. The sputum sediments were used for cytology evaluation. The study included 102 lung adenocarcinoma patients; 65 patients (63.7%) were positive for EGFR mutations in tumor samples. EGFR mutation status was positive in 30 patients (29.4%) by sputum cfDNA testing, achieving an overall sensitivity and specificity of 46.2% and 100%, respectively. Comparison of EGFR mutation status in tumor samples revealed that the sensitivity of testing sputum cfDNA in 40 patients with stage I to IIIA versus 62 patients with stage IIIB to IV was 24% (6/25) versus 65.0% (26/40). Through cytology evaluation, the sputum specimens from 62 advanced patients were classified into three categories: 10 were unsatisfactory; 34 were satisfactory but had no malignant cells; and 18 had malignant cells. The sensitivities of these three categories were 0% (0/8), 71.4% (15/21), and 100% (11/11), respectively. These findings revealed that with the improved cfDNA extraction method and sputum cytology evaluation, sputum cfDNA is a valuable surrogate sample type for detecting clinical EGFR mutations in advanced lung adenocarcinoma patients.

Circulating Tumour Cells (CTC), Head and Neck Cancer and Radiotherapy; Future Perspectives

Head and neck cancer is the seventh most common cancer in Australia and globally. Despite the current improved treatment modalities, there is still up to 50⁻60% local regional recurrence and or distant metastasis. High-resolution medical imaging technologies such as PET/CT and MRI do not currently detect the early spread of tumour cells, thus limiting the potential for effective minimal residual detection and early diagnosis. Circulating tumour cells (CTCs) are a rare subset of cells that escape from the primary tumour and enter into the bloodstream to form metastatic deposits or even re-establish themselves in the primary site of the cancer. These cells are more aggressive and accumulate gene alterations by somatic mutations that are the same or even greater than the primary tumour because of additional features acquired in the circulation. The potential application of CTC in clinical use is to acquire a liquid biopsy, by taking a reliable minimally invasive venous blood sample, for cell genotyping during radiotherapy treatment to monitor the decline in CTC detectability, and mutational changes in response to radiation resistance and radiation sensitivity. Currently, very little has been published on radiation therapy, CTC, and circulating cancer stem cells (CCSCs). The prognostic value of CTC in cancer management and personalised medicine for head and neck cancer radiotherapy patients requires a deeper understanding at the cellular level, along with other advanced technologies. With this goal, this review summarises the current research of head and neck cancer CTC, CCSC and the molecular targets for personalised radiotherapy response.

The Prognostic Role of Circulating Tumor Cells (CTCs) in Lung Cancer

Lung cancer affects over 1. 8 million people worldwide and is the leading cause of cancer related mortality globally. Currently, diagnosis of lung cancer involves a combination of imaging and invasive biopsies to confirm histopathology. Non-invasive diagnostic techniques under investigation include "liquid biopsies" through a simple blood draw to develop predictive and prognostic biomarkers. A better understanding of circulating tumor cell (CTC) dissemination mechanisms offers promising potential for the development of techniques to assist in the diagnosis of lung cancer. Enumeration and characterization of CTCs has the potential to act as a prognostic biomarker and to identify novel drug targets for a precision medicine approach to lung cancer care. This review will focus on the current status of CTCs and their potential diagnostic and prognostic utility in this setting.

Circulating cell-free microRNAs as clinical cancer biomarkers

MicroRNAs (miRNAs) are non-coding small RNAs that are master regulators of genic expression and consequently of many cellular processes. But their expression is often deregulated in human tumors leading to cancer development. Recently miRNAs were discovered in body fluids (serum, plasma and others) and their levels have often been reported to be altered in patients. Circulating miRNAs became one of the most promising biomarkers in oncology for early diagnosis, prognosis and therapeutic response prediction. Here we describe the origins and roles of miRNAs, and summarize the most recent studies focusing on their usefulness as cancer biomarkers in lung, breast, colon, prostate, ovary cancers and melanoma. Lastly, we describe the main methodologies related to miRNA detection, which should be standardized for their use in clinical practice.

Diagnostic and Therapeutic Potential of MicroRNAs in Lung Cancer

Lung cancer is the leading cause of deaths resulting from cancer owing to late diagnosis and limited treatment intervention. MicroRNAs are short, non-coding RNA molecules that regulate gene expression post-transcriptionally by translational repression or target messenger RNA degradation. Accumulating evidence suggests various roles for microRNAs, including development and progression of lung cancers. Because microRNAs are degraded to a much lesser extent in formalin-fixed paraffin-embedded specimens and are present not only in tumor tissues but also in body fluids, there is an increased potential in microRNA analyses for cancer research. In this review, recent studies of microRNA are introduced and briefly summarized, with a focus on the association of microRNAs with histological subtypes, genetic driver alterations, therapeutically-targeted molecules, and carcinogens. The reported circulating microRNA signature for the early detection of lung cancer and the implications of microRNAs as the modulators of tumor immune response are also introduced.

Major Tumor Suppressor and Oncogenic Non-Coding RNAs: Clinical Relevance in Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide, yet there remains a lack of specific and sensitive tools for early diagnosis and targeted therapies. High-throughput sequencing techniques revealed that non-coding RNAs (ncRNAs), e.g., microRNAs and long ncRNAs (lncRNAs), represent more than 80% of the transcribed human genome. Emerging evidence suggests that microRNAs and lncRNAs regulate target genes and play an important role in biological processes and signaling pathways in malignancies, including lung cancer. In lung cancer, several tumor suppressor/oncogenic microRNAs and lncRNAs function as biomarkers for metastasis and prognosis, and thus may serve as therapeutic tools. In this review, recent work on microRNAs and lncRNAs is introduced and briefly summarized with a focus on potential biological and therapeutic applications.

Tumour Heterogeneity: The Key Advantages of Single-Cell Analysis

Tumour heterogeneity refers to the fact that different tumour cells can show distinct morphological and phenotypic profiles, including cellular morphology, gene expression, metabolism, motility, proliferation and metastatic potential. This phenomenon occurs both between tumours (inter-tumour heterogeneity) and within tumours (intra-tumour heterogeneity), and it is caused by genetic and non-genetic factors. The heterogeneity of cancer cells introduces significant challenges in using molecular prognostic markers as well as for classifying patients that might benefit from specific therapies. Thus, research efforts for characterizing heterogeneity would be useful for a better understanding of the causes and progression of disease. It has been suggested that the study of heterogeneity within Circulating Tumour Cells (CTCs) could also reflect the full spectrum of mutations of the disease more accurately than a single biopsy of a primary or metastatic tumour. In previous years, many high throughput methodologies have raised for the study of heterogeneity at different levels (i.e., RNA, DNA, protein and epigenetic events). The aim of the current review is to stress clinical implications of tumour heterogeneity, as well as current available methodologies for their study, paying specific attention to those able to assess heterogeneity at the single cell level.