MicroRNA Biomarkers for Type I Diabetes

Here is a paper from several years ago suggesting that circulating microRNAs (small RNA molecules that affect gene expression) can be used to "predict and diagnose" type I diabetes before clinical symptoms are present.  Abstract:

Type 1 diabetes (T1D) is an autoimmune disease that is clinically silent until the majority of β cells are destroyed. There is an unmet need for reliable and cost-effective biomarkers to predict and diagnose diabetes at an early stage. A number of stable microRNAs (miRNAs) have been reported in serum and plasma and are now being investigated as biomarkers of different diseases. We measured the levels of 745 miRNAs in sera of children with recent-onset T1D and age-matched controls using locked nucleic acid-enhanced (LNA-enhanced) quantitative PCR profiling. Thirty-five miRNAs were significantly different between the groups, and 27 miRNAs were elevated in T1D. Good discriminating power was obtained for 6 miRNAs (miR-454-3p, miR-222-3p, miR-144-5p, miR-345-5p, miR-24-3p, and miR-140-5p), which were not elevated at later stages of diabetes. In silico pathway analysis, based on inferred miRNA target genes, associated glycosaminoglycan biosynthesis as well as PI3K/Akt, MAPK, and Wnt signaling pathways with early stages of T1D. Among the 27 upregulated miRNAs in T1D, 2 miRNAs significantly correlated with hemoglobin A1c (HbA1c), as did 5 of 8 downregulated miRNAs. A total of 134 miRNAs significantly correlated with HbA1c when stratifying hyperglycemia-induced miRNAs from T1D-specific miRNAs. In conclusion, we have identified a serum miRNA pattern of recent-onset T1D and signaling pathways that may be involved in its pathogenesis.

The same principle can apply for early diagnosis of other disorders, and we'll be looking at any progress (if any) made since this article came out.  Note also that study of microRNAs is not only useful for identifying biomarkers but also for identifying the cell signaling that is aberrant in disease (as the end of the abstract suggests), leading the way to possible novel therapies.

Diagnostic Tests And Patient Reassurance

Do diagnostic tests reassure patients?  Possibly not, abstract:

OBJECTIVE: This review is a narrative synthesis of the RCTs which studied the efficacy of using diagnostic tests to reassure patients.

METHODS: We searched for RCTs that examined the level of reassurance after diagnostic testing in outpatients. We used PubMed, Psychinfo, Cochrane Central, Ongoing Trials Database and Scopus.

RESULTS: We found 5 randomized controlled trials that included 1544 patients. The trials used different diagnostic tests (ECG, radiography of lumbar spine, MR brain scan, laboratory tests, MR of lumbar spine) for different complaints (e.g. chest pain, low back pain and headache). Four out of 5 RCTs did not find a significant reassuring value of the diagnostic tests. One study reported a reassuring effect at 3 months which had disappeared after one year.

CONCLUSION: Despite the sparse and heterogeneous studies, the results point in the direction of diagnostic tests making hardly any contribution to the level of reassurance. We recommend further studies on the use of diagnostic tests and other strategies to reassure the patient.

PRACTICE IMPLICATIONS: A clear explanation and watchful waiting can make additional diagnostic testing unnecessary. If diagnostic tests are used, it is important to provide adequate pre-test information about normal test results.

Of course, diagnostic tests (that are presumably not necessary) are not only given to reassure patients, but – possibly in some cases - to protect doctors from malpractice liability.

Another MicroRNA And Colorectal Cancer

Another microRNA has been shown to affect colorectal cancer, this time by targeting the Wnt pathway-controlling protein APC (that is typically mutated and inactivated in this form of cancer).  The microRNA may promote cancer by further decreasing APC and allowing for more deregulated Wnt signaling.  This has potential diagnostic and therapeutic applications. Abstract:

BACKGROUND:

Aberrant activation of the Wnt/β-catenin signaling pathway is frequently observed in colorectal cancer (CRC). β-catenin is the major Wnt signaling pathway effector and inactivation of adenomatous polyposis coli (APC) results in nuclear accumulation of β-catenin. It has been suggested that inactivation of APC plays an important role in activation of the Wnt/β-catenin pathway and in the progression of colorectal tumorigenesis. However, the mechanism through which APC mediates colorectal tumorigenesis is not understood. Increasing evidence suggests that the dysregulation of microRNAs (miRNAs) is involved in colorectal tumorigenesis. Although miR-494 has been reported as being an upregulated miRNA, the interplay between miR-494 and APC-mediated colorectal tumorigenesis progression remains unclear.

METHODS:

The expression of miR-494 in tissues from patients diagnosed with CRC was analyzed using a microarray and real-time PCR. The effects of miR-494 on cell proliferation and tumorigenesis in CRC cells were analyzed by flow cytometry, colony formation assays, BrdU incorporation assays, and CCK8 assays. The correlation between miR-494 expression and APC expression, as well as the mechanisms by which miR-494 regulates APC in CRC were also addressed.

RESULTS:

miR-494 was significantly upregulated in CRC tissues, and this increase was negatively associated with APC expression. APC was confirmed to be a direct target of miR-494 in CRC. Furthermore, overexpression of miR-494 induced Wnt/β-catenin signaling by targeting APC, thus promoting CRC cell growth.

CONCLUSIONS:

This study provides novel insights into the role of miR-494 in controlling CRC cell proliferation and tumorigenesis, and identifies miR-494 as a potential prognostic marker and therapeutic target.

MicroRNA Markers For Oral Cancer

MicroRNAs may possibly be used as biomarkers for oral cancer.  Early diagnosis of cancer would be helpful for treatment – catch it early. Abstract:

BACKGROUND:

Oral squamous cell carcinomas (OC) are life-threatening diseases emerging as major international health concerns.

OBJECTIVE:

Development of an efficient clinical strategy for early diagnosis of the disease is a key for reducing the death rate. Biomarkers are proven to be an effective approach for clinical diagnosis of cancer. Although mechanisms underlying regulation of oral malignancy are still unclear, microRNAs (miRNAs) as a group of small non-coded RNAs may be developed as the effective biomarkers used for early detection of oral cancer.

METHODS:

A literature search was conducted using the databases of PubMed, Web of Science, and the Cochrane Library. The following search terms were used: miRNAs and oral cancer or oral carcinoma. A critical appraisal of the included studies was performed with upregulated miRNAs and downregulated miRNAs in oral cancer.

RESULTS:

In this review, we summarize the research progress made in miRNAs for diagnosis of oral cancer. The involvement of miRNAs identified in signal transduction pathways in OC, including Ras/MAPK signaling, PI3K/AKT signaling, JAK/STAT signaling, Wnt/β-catenin signaling, Notch signaling, and TGF-β/SMAD signaling pathway.

CONCLUSIONS:

A number of studies demonstrated that miRNAs may be developed as an ideal set of biomarkers used for early diagnosis and prognosis of cancers because of the stability in human peripheral blood and body fluids and availability of non-invasive approaches being developed for clinical utility.

CLINICAL RELEVANCE:

These findings suggest that miRNAs as biomarkers may be useful for diagnosis of OC.

Circulating Tumor DNA Fail?

Some bad news: not much evidence to support the current use of circulating tumor DNA assays; more work is required.  Abstract:

Purpose Clinical use of analytical tests to assess genomic variants in circulating tumor DNA (ctDNA) is increasing. This joint review from ASCO and the College of American Pathologists summarizes current information about clinical ctDNA assays and provides a framework for future research. Methods An Expert Panel conducted a literature review on the use of ctDNA assays for solid tumors, including pre-analytical variables, analytical validity, interpretation and reporting, and clinical validity and utility. Results The literature search identified 1,338 references. Of those, 390, plus 31 references supplied by the Expert Panel, were selected for full-text review. There were 77 articles selected for inclusion. Conclusion The evidence indicates that testing for ctDNA is optimally performed on plasma collected in cell stabilization or EDTA tubes, with EDTA tubes processed within 6 hours of collection. Some ctDNA assays have demonstrated clinical validity and utility with certain types of advanced cancer; however, there is insufficient evidence of clinical validity and utility for the majority of ctDNA assays in advanced cancer. Evidence shows discordance between the results of ctDNA assays and genotyping tumor specimens and supports tumor tissue genotyping to confirm undetected results from ctDNA tests. There is no evidence of clinical utility and little evidence of clinical validity of ctDNA assays in early-stage cancer, treatment monitoring, or residual disease detection. There is no evidence of clinical validity and clinical utility to suggest that ctDNA assays are useful for cancer screening, outside of a clinical trial. Given the rapid pace of research, re-evaluation of the literature will shortly be required, along with the development of tools and guidance for clinical practice

Introducing CancerSEEK

A blood test, CancerSEEK, has shown some efficacy in detecting a variety of cancer types, including some for which screening is currently difficult or impossible (although stomach, which is listed by them in that category, can be interrogated by upper GI endoscopy or barium imaging).  Interesting, some data can be obtained from this blood test to actually localize where the tumor is to a small number of anatomic locations for the types of cancer studied.  This is a promising diagnostic tool.  Abstract:

Earlier detection is key to reducing cancer deaths. Here we describe a blood test that can detect eight common cancer types through assessment of the levels of circulating proteins and mutations in cell-free DNA. We applied this test, called CancerSEEK, to 1,005 patients with non-metastatic, clinically detected cancers of the ovary, liver, stomach, pancreas, esophagus, colorectum, lung, or breast. CancerSEEK tests were positive in a median of 70% of the eight cancer types. The sensitivities ranged from 69% to 98% for the detection of five cancer types (ovary, liver, stomach, pancreas, and esophagus) for which there are no screening tests available for average-risk individuals. The specificity of CancerSEEK was > 99%: only 7 of 812 healthy controls scored positive. In addition, CancerSEEK localized the cancer to a small number of anatomic sites in a median of 83% of the patients.

Not diagnosed? Search CrowdMed

I have previously written about sourcing of diagnosis, but this recent post came out and I decided that the idea is worth sharing again.

Detection Of Early Stage Cancers Using Circulating Tumor DNA.

One "holy grail" of cancer diagnostics is the development of a non-invasive (e.g., blood) test that can detect early stage cancers.  Some progress has been made; from the abstract

Evaluation of 200 patients with colorectal, breast, lung, or ovarian cancer detected somatic mutations in the plasma of 71, 59, 59, and 68%, respectively, of patients with stage I or II disease…These analyses provide a broadly applicable approach for noninvasive detection of early-stage tumors that may be useful for screening and management of patients with cancer.

Therefore, tumor DNA. and its diagnostic mutations, can be found in the plasma of a majority of patients with early stage cancers.  That is good news, and we await further refinement of this approach.

Non-Invasive Blood Test For Pancreatic Cancer: Early Study

One reason pancreatic cancer is so deadly is that it is usually diagnosed late, giving few or no symptoms in its early stages. Development of a non-invasive test – such as a blood test – for this cancer is therefore imperative.  Some developments are shown in this study.  A sensitivity of 64% is obviously not perfect and can stand improvement, but is certainly better than having no test at all and it is a solid starting point for further improvement.  The 99.5% specificity (demonstrating a very low probability of false positives) is excellent.  Abstract:

The earlier diagnosis of cancer is one of the keys to reducing cancer deaths in the future. Here we describe our efforts to develop a noninvasive blood test for the detection of pancreatic ductal adenocarcinoma. We combined blood tests for KRAS gene mutations with carefully thresholded protein biomarkers to determine whether the combination of these markers was superior to any single marker. The cohort tested included 221 patients with resectable pancreatic ductal adenocarcinomas and 182 control patients without known cancer. KRAS mutations were detected in the plasma of 66 patients (30%), and every mutation found in the plasma was identical to that subsequently found in the patient's primary tumor (100% concordance). The use of KRAS in conjunction with four thresholded protein biomarkers increased the sensitivity to 64%. Only one of the 182 plasma samples from the control cohort was positive for any of the DNA or protein biomarkers (99.5% specificity). This combinatorial approach may prove useful for the earlier detection of many cancer types.

Are you sick and still searching for diagnosis?

Today I found out about CrowdMed. It seems that the company was founded in 2012-2013. It facilitates individuals in finding out their true diagnosis. I am still navigating through the website to find out how this is accomplished, but it seems that one needs to pay a fee in order to post his/her case and obtain the opinion of medical experts.

Considering the horror stories I have heard about misdiagnosis or late diagnosis, the concept of CrowdMed does fill a niche. How successful and useful the approach is, I do not know.

If you have any opinion, please share here.

A useful website for individuals with already confirmed diagnosis is PatientsLikeMe, where people share knowledge about their conditions, treatments, etc. Again, I have not used it; therefore, if you have any opinion on the service, please share.