PRELIMINARY RESULTS OF lncRNAs AS BIOMARKERS FOR COLORECTAL CANCER DIAGNOSIS

Introduction

lncRNAs are strands larger than 200 nucleotides that do not encode proteins. They have regulatory functions in cell proliferation, apoptosis and migration. They are stable over a long period and may have diagnostic value in colorectal cancer (CRC). Their availability as effective biomarkers for CRC screening would represent a substantial advance, as tests could be performed with minimal risk and wide acceptance. The aim of this study is to evaluate selected lncRNAs in plasma as potential diagnostic biomarkers in CRC.

Methods

Prospective cohort study between patients operated on for CRC (cases) and healthy patients (controls). Blood samples were processed in the biobank to obtain plasma by centrifugation. Subsequently, the levels of three CRC-related lncRNAs (HOTAIR, CCAT2 and PVT1) were determined in the laboratory of the Electroanalysis Group of the University of Oviedo (GEUO).

Results

In the initial results, an overexpression of the three genes (HOTAIR, CCAT2 and PVT1) was observed in CRC patients, with HOTAIR being the one that best differentiates between CRC and healthy patients. In addition, the combined determination of the three lncRNAs could obtain better results than the individual determination of each of them.

Conclusions

The lncRNAs studied are overexpressed in the CRC patient sample. The sample size needs to be increased to confirm this trend. It is logical to postulate that molecular technologies will lead to the development of better screening modalities and individualised treatments.

FUNCTIONAL MAPPING OF NOVEL HISTONE POST-TRANSLATIONAL ALTERATIONS IN COLON CANCER

Introduction

Epigenetic alterations are related to the process of tumorigenesis and resistance to oncological therapies. Although more than 60 types of histone post-translational modifications (HPTMs) have been described, the alterations that manifest simultaneously in tumor tissue have not been systematically studied in colorectal cancer (CRC). This project aims to develop a new screening methodology to delineate epigenetic alterations present in CRC and to obtain a set of biomarkers related to malignancy and tumor response.

Methods

Using state-of-the-art tandem mass spectrometry (MS-MS) techniques, a direct injection protocol will be performed to simultaneously identify the presence of >200 HPTMs-related peptides in a cohort of primary tumors and paired healthy CRC tissue. Patterning of spectra and statistical analyses will be performed with the automated processing algorithm EpiProfile 2.0.

Results

A histone extraction protocol optimized for human tumor samples was developed. Likewise, we managed to make MS/MS sample processing more flexible by implementing a multiplatform workflow (Thermo / Sciex), which will increase the screening and data analysis capacity. Through this process we managed to detect >200 peptides related to HPTMs in control samples, and we observed significant differences in certain HPTMs with pharmacological treatments in primary cultures.

Conclusions

These results will allow the identification of epigenetic biomarkers related to grade, stage and recurrence in the context of CRC.

MICROVESICLE SURFACE PROTEIN DETECTION AS A POTENTIAL BIOMARKER IN COLORECTAL CANCER

Introduction

Colorectal cancer (CRC) is the third leading cause of death from cancer in the world; early detection is a key factor for patient´s prognosis. Microvesicles (MVs) are subcellular structures delimited by lipid bilayer intimately involved in physio-pathological processes such as cancer. Our objective is the characterization and detection of surface proteins in plasma derived MVs, as well as their usefulness as a tool in the detection of CRC.

Methods

Circulating MVs in peripheral blood of healthy individuals, with adenomas, high grade adenoma or carcinoma were isolated and characterized. MVs CD9, CD147 and EpCaM MVs surface proteins quantification was performed using an innovative lateral flow immunoassay (LFIA) developed in our laboratory.

Results

The characterization of the plasma MVs confirmed our previous observations, presenting a lower concentration of MVs in the groups of high-grade adenoma and mainly CRC. However, the carcinoma group presents a higher amount of protein per MV suggesting a greater MV´s complexity in this group. The analysis of surface antigens by LFIA show an unexpectedly significant reduction of these proteins in the carcinoma group.

Conclusions

The detection of antigens on the surface of MVs by LFIA may be able to discriminate patients with CRC and could emerge as an alternative test that complements CRC screening programs.

IDENTIFICATION OF EPIGENETIC VULNERABILITIES IN THE ADENOMA-CARCINOMA SEQUENCE

Introduction

Numerous studies have documented the functional effect of different driver mutations on the development and progression of colorectal cancer (CRC). However, the molecular-level impact of each of these mutations on the epigenome/transcriptome, as well as the phenotype-related longitudinal effects of these mutations have not been characterized in detail. This work proposes an experimental design based on the integration of different -omic layers in order to identify molecular vulnerabilities with therapeutic potential in the adenoma-carcinoma sequence.

Methods

The proposed experimental model contemplates the introduction of sequential mutations in the APC/KRAS/TP53 and SMAD4 genes with CRISPR/Cas9 technology in human colon organoids obtained from healthy mucosa. To determine the molecular alterations at each step of the sequence, a paired RNA expression and DNA methylation analysis will be performed at the whole genome level with the respective massive next-generation sequencing technologies / EPIC arrays. Finally, to identify possible functional associations between the epigenome/transcriptome, an integration analysis of these -omics will be performed with novel computational algorithms, also including the integration of these data with information available from international consortia.

Results

The project is currently in the initial stages of development. The model and the most updated results available to date will be discussed in detail during the congress.

Conclusions

These results will allow the identification of molecular vulnerabilities with therapeutic potential in the context of CRC.

NLR AND PLR: NEW PREDICTORS OF COMPLICATED DIVERTICULITIS AND THE NEED FOR INTERVENTION

Introduction

The most commonly used analytical parameters to predict severity (CRP, PCT, leukocyte count, % neutrophils…) are well known, whereas biomarkers such as the neutrophil-lymphocyte index (NLR) and the platelet-lymphocyte index (PLR) are less known and have utility during the diagnosis of acute diverticulitis (AD).

Methods

Retrospective study of 176 patients diagnosed with AD during 2019. The association between multiple acute phase reactants (PLRs) and the presence of complication of AD was studied.

Results

The mean age was 62.8 years, being more frequent in women (59.7%). According to the Hinchey classification 46 (26.1%) AD were complicated; Hinchey Ib: 32 (18.2%), Hinchey II: 10 (5.7%), Hinchey III: 3 (1.7%) and Hinchey IV: 1 (0.6%). Of all of them, 14 patients required surgery.

A statistically significant increase in all RFA was observed in complicated AD and in cases of invasive treatment.

It was shown that CRP has greater discriminative power to detect complicated AD with ROC curves (AUC: 76.6% (95% CI: 0.676–0.856)). However, regarding the need for invasive treatment, the NLR (AUC 77.8%; 95% CI: 0.648–0.908) was found to be more accurate.

For the classification of uncomplicated vs. complicated AD, the cut-off points were CRP (9.05), NLR (6.23) and PLR (141.93), with CRP being the most accurate.

Conclusions

The NLR and PLR are easy and inexpensive indices to obtain to diagnose AD and their accuracy is comparable to that of other RFA commonly used in diagnosis.

TELEMENTORING IN TIMES OF COVID-19 FOR TRAINING IN GENERAL SURGERY

INTRODUCTION

Telemedicine applied to surgery is called telementorization (TM). It allows remote assistance by expert surgeons to others with less experience in certain techniques, thus guaranteeing learning that overcomes the barriers of time and location without being associated with a higher rate of complications. The objective is to publicize the use of this type of technology in our surgical department, particularly needed with the current restrictions.

MATERIAL AND METHODS

In our center, the Proximie platform (www.proximie.com) is used as a tool for TM. It allows to remotely broadcast live procedures performed by expert surgeons, as well as to create a virtual library of our own procedures that can be used as study and teaching tool by residents. This platform transmits not only bidirectional image and sound, but it also allows the active participation of a remote assistant with interactive features that are projected directly on the screen of the local surgeon.

RESULTS

The Proximie platform is being used frequently (and more intensively during this time of greatest restrictions) in advanced colorectal surgeries, with TM by remote experts and in our department for the continuing training program for residents. It also offers the possibility of conducting multidisciplinary sessions and webinars with subsequent availability control online.

CONCLUSIONS

TM and digital platforms such as Proximie provide important benefits in the practical learning and training of surgeons, especially with the current restrictions, being a safe technique and a teaching tool to be exploited.

SURGICAL DIFFICULTY AND PELVIMETRY IN RECTAL CANCER. IS IT USEFUL?

INTRODUCTION

Different difficulty factors have been described in rectal cancer surgery as BMI, male gender, tumor height, neoadjuvant treatment or narrow pelvis. Pelvimetry is not a routine preoperative study in rectal cancer.

MATERIAL AND METHODS

Retrospective observational study in 228 patients. Operative time was evaluated as a difficult surgical parameter and its relationship with pelvimetric variables was studied.

RESULTS

Our average operative time was 255,4 ± 65,8 minutes. Significant results were found with regard to patients’ BMI, distance to the anal margin, type of approach, need for neoadjuvant therapy and the following pelvimetry parameters. In the univariate analysis, the parameters were pubis height, pelvis depth, angle of the right levator in coronal plane, the ratio of the pelvis inlet diameter with respect to its depth, the ratio of the angle promontory-S3-coccyx with respect to the angle S3-coccyx-lower border of the pubis and the ratio of the area of the mesorectum to the area of the pelvis in the sagittal plane. In multivariate analysis, the variables that most influenced the surgical time were the type of approach, the BMI, the location of the tumor, the intraoperative complications and the ratio of the mesorectum area to the area of the pelvis in the sagittal plane.

CONCLUSION

Pelvimetry is a simple tool that completes preoperative studies and also obtains better surgical planning in complex pelvises.

POTENTIAL OF EXTRACELLULAR MICROVESICLES AS NEW COLORECTAL CANCER BIOMARKER

INTRODUCTION

Colorectal cancer (CRC) is the third leading cause of cancer death and the fourth cancer with the highest incidence in the world; early detection is a key factor for patient´s prognosis. Microvesicles (MVs) are subcellular structures delimited by lipid bilayer intimately involved in physiopathological processes such as cancer. Our objective is to study the potential of microvesicles as new biomarkers in CRC.

MATERIAL AND METHODS

Blood was prospectively collected from 300 patients recruited during diagnostic colonoscopy. They were classified into control (no pathological findings), adenoma, high-grade adenoma or carcinoma groups. Microvesicles were isolated from patients serum and a selected cohort of samples was used for MVs characterization and the CD174 surface antigen detection by lateral flow immunoassay (LFI).

RESULTS

Mean age of the patients was 62.79 (SD 7.662), being 90% asymptomatic at the time of recruitment. The mean size of isolated microparticles was similar in all groups, although larger variability was observed in carcinoma group. MVs concentration is considerably lower in high-grade adenoma and CRC compared to control group. CRC associated surface antigen CD147 can be consistently detected on the surface of microvesicles by lateral flow immunoassay technique

CONCLUSION

The preliminary results of this project show that it is possible use MVs as diagnostic / prognostic markers. Likewise, is feasible the develop of rapid tests using IFL technology that could be used to complement and/or replace current detection techniques.