Evaluation of serum nucleoside diphosphate kinase A for the detection of colorectal cancer

Immune-like sandwich multiple hotspots SERS biosensor for ultrasensitive detection of NDKA biomarker in serum

Developing the rapid, specific, and sensitive tumor marker NDKA biosensor has become an urgent need in the field of early diagnosis of colorectal cancer (CRC). Surface-enhanced Raman spectroscopy (SERS) with the advantages of high sensitivity, high resolution as well as providing sample fingerprint, enables rapid and sensitive detection of tumor markers. However, many SERS biosensors rely on boosting the quantity of Raman reporter molecules on individual nanoparticle surfaces, which can result in nanoparticle agglomeration, diminishing the stability and sensitivity of NDKA detection. Here, we proposed an immune-like sandwich multiple hotspots SERS biosensor for highly sensitive and stable analysis of NDKA in serum based on molecularly imprinted polymers and NDKA antibody. The SERS biosensor employs an array of gold nanoparticles, which are coated with a biocompatible polydopamine molecularly imprinted polymer as a substrate to specifically capture NDKA. Then the biosensor detects NDKA through Raman signals as a result of the specific binding of NDKA to the SERS nanotag affixed to the capture substrate along with the formation of multiple hotspots. This SERS biosensor not only avoids the aggregation of nanoparticles but also presents a solution to the obstacles encountered in immune strategies for certain proteins lacking multiple antibody or aptamer binding sites. Furthermore, the practical application of the SERS biosensor is validated by the detection of NDKA in serum with the lower limit of detection (LOD) of 0.25 pg/mL, meanwhile can detect NDKA of 10 ng/mL in mixed proteins solution, illustrating high sensitivity and specificity. This immune-like sandwich multiple hotspots biosensor makes it quite useful for the early detection of CRC and also provides new ideas for cancer biomarker sensing strategy in the future.

PRUNE1 and NME/NDPK family proteins influence energy metabolism and signaling in cancer metastases

We describe here the molecular basis of the complex formation of PRUNE1 with the tumor metastasis suppressors NME1 and NME2, two isoforms appertaining to the nucleoside diphosphate kinase (NDPK) enzyme family, and how this complex regulates signaling the immune system and energy metabolism, thereby shaping the tumor microenvironment (TME). Disrupting the interaction between NME1/2 and PRUNE1, as suggested, holds the potential to be an excellent therapeutic target for the treatment of cancer and the inhibition of metastasis dissemination. Furthermore, we postulate an interaction and regulation of the other Class I NME proteins, NME3 and NME4 proteins, with PRUNE1 and discuss potential functions. Class I NME1-4 proteins are NTP/NDP transphosphorylases required for balancing the intracellular pools of nucleotide diphosphates and triphosphates. They regulate different cellular functions by interacting with a large variety of other proteins, and in cancer and metastasis processes, they can exert pro- and anti-oncogenic properties depending on the cellular context. In this review, we therefore additionally discuss general aspects of class1 NME and PRUNE1 molecular structures as well as their posttranslational modifications and subcellular localization. The current knowledge on the contributions of PRUNE1 as well as NME proteins to signaling cascades is summarized with a special regard to cancer and metastasis.

Progress in the field of noninvasive diagnostics for colorectal cancer: a systematic review for the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions

BACKGROUND

Early detection of pre-cancerous adenomas through screening can reduce colorectal cancer (CRC) incidence. Fecal immunochemical tests are commonly used, but have limited sensitivity for pre-cancerous lesions. Blood-based screening may improve test sensitivity. This systematic review and meta-analysis was conducted to evaluate the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions.

RESEARCH DESIGN AND METHODS

We present the accuracy of blood-based biomarkers for the detection of advanced pre-cancerous lesions. EMBASE, Web of Science and PubMed databases were searched, with study populations limited to adults diagnosed with advanced pre-cancerous lesions at colonoscopy, who had a blood-based biomarker test analyzed with reports of sensitivity and specificity.

RESULTS

69 studies were identified, which assessed 133 unique biomarkers sets. The best performing test was a panel of 6 miRNAs, with a sensitivity of 95% and specificity of 90% for advanced pre-cancerous lesions. Only 6 biomarkers demonstrated sensitivity ≥ 50% and specificity ≥ 90% for the detection of advanced pre-cancerous lesions.

CONCLUSION

Many different blood-based biomarkers have been assessed for detection of advanced pre-cancerous lesions, but few have progressed beyond the discovery stage. While some biomarkers have reported high sensitivity and specificity, larger prospective studies in unbiased intended-use screening populations are required for validation.

Variation of Positive Predictive Values of Fecal Immunochemical Tests by Polygenic Risk Score in a Large Screening Cohort

INTRODUCTION

Prevalence of colorectal neoplasms varies by polygenic risk scores (PRS). We aimed to assess to what extent a PRS might be relevant for defining personalized cutoff values for fecal immunochemical tests (FITs) in colorectal cancer screening.

METHODS

Among 5,306 participants of screening colonoscopy who provided a stool sample for a quantitative FIT (Ridascreen Hemoglobin or FOB Gold) before colonoscopy, a PRS was determined, based on the number of risk alleles in 140 single nucleotide polymorphisms. Subjects were classified into low, medium, and high genetic risk of colorectal neoplasms according to PRS tertiles. We calculated positive predictive values (PPVs) and numbers needed to scope (NNS) to detect 1 advanced neoplasm (AN) by the risk group, and cutoff variation needed to achieve comparable PPVs across risk groups in the samples tested with Ridascreen (N = 1,271) and FOB Gold (N = 4,035) independently, using cutoffs yielding 85%, 90%, or 95% specificity.

RESULTS

Performance of both FITs was very similar within each PRS group. For a given cutoff, PPVs were consistently higher by 11%-15% units in the high-risk PRS group compared with the low-risk group (all P values < 0.05). Correspondingly, NNS to detect 1 advanced neoplasm varied from 2 (high PRS, high cutoff) to 5 (low PRS, low cutoff). Conversely, very different FIT cutoffs would be needed to ensure comparable PPVs across PRS groups.

DISCUSSION

PPVs and NNS of FITs varied widely across people with high and low genetic risk score. Further research should evaluate the relevance of these differences for personalized colorectal cancer screening.

Extracellular Vesicle-Mediated Purinergic Signaling Contributes to Host Microenvironment Plasticity and Metastasis in Triple Negative Breast Cancer

Metastasis accounts for over 90% of cancer-related deaths, yet the mechanisms guiding this process remain unclear. Secreted nucleoside diphosphate kinase A and B (NDPK) support breast cancer metastasis. Proteomic evidence confirms their presence in breast cancer-derived extracellular vesicles (EVs). We investigated the role of EV-associated NDPK in modulating the host microenvironment in favor of pre-metastatic niche formation. We measured NDPK expression and activity in EVs isolated from triple-negative breast cancer (MDA-MB-231) and non-tumorigenic mammary epithelial (HME1) cells using flow cytometry, western blot, and ATP assay. We evaluated the effects of EV-associated NDPK on endothelial cell migration, vascular remodeling, and metastasis. We further assessed MDA-MB-231 EV-induced proteomic changes in support of pre-metastatic lung niche formation. NDPK-B expression and phosphotransferase activity were enriched in MDA-MB-231 EVs that promote vascular endothelial cell migration and disrupt monolayer integrity. MDA-MB-231 EV-treated mice demonstrate pulmonary vascular leakage and enhanced experimental lung metastasis, whereas treatment with an NDPK inhibitor or a P2Y1 purinoreceptor antagonist blunts these effects. We identified perturbations to the purinergic signaling pathway in experimental lungs, lending evidence to support a role for EV-associated NDPK-B in lung pre-metastatic niche formation and metastatic outgrowth. These studies prompt further evaluation of NDPK-mediated EV signaling using targeted genetic silencing approaches.

Biomarker discovery study of inflammatory proteins for colorectal cancer early detection demonstrated importance of screening setting validation

OBJECTIVES

Most studies identifying inflammatory markers for early detection of colorectal cancer (CRC) were conducted using clinically manifest cases. We aimed to identify circulating inflammatory biomarkers for early detection of CRC and validate them in both a clinical setting and a true screening setting.

STUDY DESIGN AND SETTING

A total of 92 inflammatory proteins were quantified in baseline plasma samples from individuals clinically diagnosed with CRC and neoplasm-free controls matched on age and sex (training set). A multimarker panel was selected and evaluated in samples from another clinical setting (validation set C) and a screening setting (validation set S).

RESULTS

In the training set (N = 330), a five-biomarker signature was selected that provided an area under curve (AUC) of 0.85 and 60.9% sensitivity to detect CRC at 90% specificity. When this algorithm was applied to validation set C (N = 318), the AUC (0.80) and sensitivity (49.5%) at 90% specificity for CRC diagnosis were only slightly lower than those in the training set. By contrast, the diagnostic performance of the algorithm in validation set S (N = 126) from a true screening setting was much poorer, with an AUC of 0.59 and a sensitivity of 28.6% at 90% specificity.

CONCLUSIONS

An inflammation-related protein panel with apparently good diagnostic properties for CRC detection was identified and confirmed in an independent clinical validation set. However, the biomarker combination performed substantially worse in a validation sample from a true screening setting. Our results underline the importance of validation in screening settings subsequently to novel signature discovery for cancer early detection.

Proteomic Profiling for Colorectal Cancer Biomarker Discovery

Nowadays, the ideal biomarker for colorectal cancer (CRC) has not been found. Two-dimensional electrophoresis (2-DE) and mass spectrometry (MS) are suitable techniques for searching new biomarkers. In this chapter, we describe methodology for biomarker discovery based on a proteomic approach. In addition, special attention is given to the sample preparation, including protein extraction, fractionation, and cleanup, as we consider this a critical step. Comparing the proteomic profile of tumor and mucosa, we identified the nucleoside diphosphate kinase A (NDKA) protein as a candidate biomarker for CRC. Finally, we validated NDKA with an ELISA kit using serum samples from individuals of a screening cohort. Our results suggest that serum NDKA is a potential biomarker for screening of CRC and premalignant advanced adenomas (AA).

"Inverse Drug Discovery" Strategy To Identify Proteins That Are Targeted by Latent Electrophiles As Exemplified by Aryl Fluorosulfates

Drug candidates are generally discovered using biochemical screens employing an isolated target protein or by utilizing cell-based phenotypic assays. Both noncovalent and covalent hits emerge from such endeavors. Herein, we exemplify an "Inverse Drug Discovery" strategy in which organic compounds of intermediate complexity harboring weak, but activatable, electrophiles are matched with the protein(s) they react with in cells or cell lysate. An alkyne substructure in each candidate small molecule enables affinity chromatography-mass spectrometry, which produces a list of proteins that each distinct compound reacts with. A notable feature of this approach is that it is agnostic with respect to the cellular proteins targeted. To illustrate this strategy, we employed aryl fluorosulfates, an underexplored class of sulfur(VI) halides, that are generally unreactive unless activated by protein binding. Reversible aryl fluorosulfate binding, correct juxtaposition of protein side chain functional groups, and transition-state stabilization of the S(VI) exchange reaction all seem to be critical for conjugate formation. The aryl fluorosulfates studied thus far exhibit chemoselective reactivity toward Lys and, particularly, Tyr side chains, and can be used to target nonenzymes (e.g., a hormone carrier or a small-molecule carrier protein) as well as enzymes. The "Inverse Drug Discovery" strategy should be particularly attractive as a means to explore latent electrophiles not typically used in medicinal chemistry efforts, until one reacts with a protein target of exceptional interest. Structure-activity data can then be used to enhance the selectivity of conjugate formation or the covalent probe can be used as a competitor to develop noncovalent drug candidates. Here we use the "Inverse Drug Discovery" platform to identify and validate covalent ligands for 11 different human proteins. In the case of one of these proteins, we have identified and validated a small-molecule probe for the first time.

Fecal immunochemical tests in combination with blood tests for colorectal cancer and advanced adenoma detection-systematic review

Background

Colorectal cancer (CRC) is a common but largely preventable cancer. Although fecal immunochemical tests (FITs) detect the majority of CRCs, they miss some of the cancers and most advanced adenomas (AAs). The potential of blood tests in complementing FITs for the detection of CRC or AA has not yet been systematically investigated.

Methods

We conducted a systematic review of performance of FIT combined with an additional blood test for CRC and AA detection versus FIT alone. PubMed and Web of Science were searched until June 9, 2017.

Results

Some markers substantially increased sensitivity for CRC when combined with FIT, albeit typically at a major loss of specificity. For AA, no relevant increase in sensitivity could be achieved.

Conclusion

Combining FIT and blood tests might be a promising approach to enhance sensitivity of CRC screening, but comprehensive evaluation of promising marker combinations in screening populations is needed.