Phenotypic plasticity underlies local invasion and distant metastasis in colon cancer

Phenotypic plasticity represents the most relevant hallmark of the carcinoma cell as it bestows it with the capacity of transiently altering its morphological and functional features while en route to the metastatic site. However, the study of phenotypic plasticity is hindered by the rarity of these events within primary lesions and by the lack of experimental models. Here, we identified a subpopulation of phenotypic plastic colon cancer cells: EpCAMlo cells are motile, invasive, chemo-resistant, and highly metastatic. EpCAMlo bulk and single-cell RNAseq analysis indicated (1) enhanced Wnt/β-catenin signaling, (2) a broad spectrum of degrees of epithelial to mesenchymal transition (EMT) activation including hybrid E/M states (partial EMT) with highly plastic features, and (3) high correlation with the CMS4 subtype, accounting for colon cancer cases with poor prognosis and a pronounced stromal component. Of note, a signature of genes specifically expressed in EpCAMlo cancer cells is highly predictive of overall survival in tumors other than CMS4, thus highlighting the relevance of quasi-mesenchymal tumor cells across the spectrum of colon cancers. Enhanced Wnt and the downstream EMT activation represent key events in eliciting phenotypic plasticity along the invasive front of primary colon carcinomas. Distinct sets of epithelial and mesenchymal genes define transcriptional trajectories through which state transitions arise. pEMT cells, often earmarked by the extracellular matrix glycoprotein SPARC together with nuclear ZEB1 and β-catenin along the invasive front of primary colon carcinomas, are predicted to represent the origin of these (de)differentiation routes through biologically distinct cellular states and to underlie the phenotypic plasticity of colon cancer cells.

Prevalence of PD-L1 expression is associated with EMAST, density of peritumoral T-cells and recurrence-free survival in operable non-metastatic colorectal cancer

INTRODUCTION

Microsatellite instability (MSI) predict response to anti-PD1 immunotherapy in colorectal cancer (CRC). CRCs with MSI have higher infiltration of immune cells related to a better survival. Elevated Microsatellite Alterations at Tetranucleotides (EMAST) is a form of MSI but its association with PD-L1 expression and immune-cell infiltration is not known.

METHODS

A consecutive, observational cohort of patients undergoing surgery for CRC. EMAST and clinicopathological characteristics were investigated against PD-L1, as well as CD3 and CD8 expression in the invasive margin or tumour centre (Immunoscore). Difference in survival between groups was assessed by log rank test.

RESULTS

A total of 149 stage I-III CRCs patients, with a median follow up of 60.1 months. Patients with PD-L1+ tumours (7%) were older (median 79 vs 71 years, p = 0.045) and had EMAST+ cancers (OR 10.7, 95% CI 2.2-51.4, p = 0.001). Recurrence-free survival was longer in cancers with PD-L1+ immune cells (HR 0.35, 95% CI 0.16-0.76, p = 0.008, independent of EMAST) and high Immunoscore (HR 0.10, 95% CI 0.01-0.72, p = 0.022). Patients expressing PD-L1 in immune cells had longer disease-specific survival (HR 0.28, 95% CI 0.10-0.77, p = 0.014).

CONCLUSIONS

Higher Immunoscore (CD3/CD8 cells) and expression of tumour PD-L1 is found in CRCs with EMAST. Lymphocytic infiltrate and peritumoral PD-L1 expression have prognostic value in CRC.

Elevated Microsatellite Alterations at Selected Tetranucleotides (EMAST) Is Not Attributed to MSH3 Loss in Stage I-III Colon cancer: An Automated, Digitalized Assessment by Immunohistochemistry of Whole Slides and Hot Spots

INTRODUCTION

EMAST is a poorly understood form of microsatellite instability (MSI) in colorectal cancer (CRC) for which loss of MSH3 has been proposed as the underlying mechanism, based on experimental studies. We aimed to evaluate whether MSH3 loss is associated with EMAST in CRC.

METHODS

A consecutive cohort of patients with stage I-III CRC. Digital image analysis using heatmap-derived hot spots investigated MSH3 expression by immunohistochemistry. Fragment analysis of multiplex PCR was used to assess MSI and EMAST, and results cross-examined with MSH3 protein expression.

RESULTS

Of 152 patients, EMAST was found in 50 (33%) and exclusively in the colon. Most EMAST-positive cancers had instability at all 5 markers, and EMAST overlapped with MSI-H in 42/50 cases (84%). The most frequently altered tetranucleotide markers were D8S321 (38.2% of tumors) and D20S82 (34.4%). Subjective evaluation of MSH3 expression by IHC in tumor found ≤10% negative tumor cells in all samples, most being ≤5% negative. Digital analysis improved the detection but showed a similar spread of MSH3 loss (range 0.1-15.7%, mean 2.2%). Hotspot MSH3 negativity ranged between 0.1 to 95.0%, (mean 8.6%) with significant correlation with the whole slide analysis (Spearman's rho=0.677 P<.001). Loss of MSH3 expression did not correlate with EMAST.

CONCLUSIONS

In a well-defined cohort of patients with CRC, loss of MSH3 was not associated with EMAST. Further investigation into the mechanisms leading to EMAST in CRC is needed.

Elevated Microsatellite Alterations at Selected Tetranucleotides (EMAST) in Colorectal Cancer is Associated with an Elderly, Frail Phenotype and Improved Recurrence-Free Survival

BACKGROUND

Elevated microsatellite alterations at selected tetranucleotides (EMAST) is a poorly investigated form of microsatellite instability (MSI) in colorectal cancer (CRC).

OBJECTIVE

The aim of this study was to investigate the clinicopathological features of EMAST in CRC and its relation to outcome.

METHODS

A population-based, consecutive cohort of surgically treated stage I-III CRC patients investigated for high-frequency MSI (MSI-H) and EMAST. Clinicopathological differences were reported as odds ratios (OR) and survival was presented as hazard ratios (HR) with 95% confidence intervals (CIs).

RESULTS

Of 161 patients included, 25% were aged > 79 years. There was a large overlap in the prevalence of EMAST (31.7%) and MSI-H (27.3%) [82.4% of EMAST were also MSI-H]. EMAST had the highest prevalence in the proximal colon (OR 15.9, 95% CI 5.6-45.1; p < 0.001) and in women (OR 4.1, 95% CI 1.9-8.6; p < 0.001), and were poorly differentiated (OR 5.0, 95% CI 2.3-10.7; p < 0.001). Compared with EMAST-negative patients, EMAST-positive patients were older (median age 77 vs. 69 years; p < 0.001), leaner (median weight 67.5 vs. 77 kg; p = 0.001), had significantly higher rates of hypoalbuminemia (24% vs. 6%; OR 2.3, 95% CI 1.5-3.6; p = 0.002) and anemia (45% vs. 20%; OR 3.3, 95% CI 1.6-6.8; p = 0.001), and had elevated preoperative C-reactive protein (CRP) levels (51% vs. 34%; OR 1.9, 95% CI 1.0-3.9; p = 0.046). Improved recurrence-free survival was found in both MSI-H and EMAST subtypes. In multivariable analysis, node status (pN +), together with elevated CRP and MSI-positive, were the strongest prognostic factors for recurrence-free survival.

CONCLUSIONS

EMAST in CRC is associated with an older, leaner, and frailer phenotype with a lower risk of recurrence. The relevance of, and putative mechanisms to, EMAST warrants further investigation.

Comparison of Three Methods for Eliciting Phonological Processes

Eight articulatory disordered children were studied to compare the occurrence of phonological processes using three elicitation methods, including single-word productions, imitated sentences, and continuous speech sampling. A total of 11 phonological processes were shown by the subjects, with only the process of gliding indicative of significantly different rates of occurrence among the three procedures. These subjects were relatively consistent in their use of phonological processes under different speaking conditions.

Assessment of clinically related outcomes and biomarker analysis for translational integration in colorectal cancer (ACROBATICC): study protocol for a population-based, consecutive cohort of surgically treated colorectal cancers and resected colorectal liver metastasis

Background

More accurate predictive and prognostic biomarkers for patients with colorectal cancer (CRC) primaries or colorectal liver metastasis (CLM) are needed. Outside clinical trials, the translational integration of emerging pathways and novel techniques should facilitate exploration of biomarkers for improved staging and prognosis.

Methods

An observational study exploring predictive and prognostic biomarkers in a population-based, consecutive cohort of surgically treated colorectal cancers and resected colorectal liver metastases. Long-term outcomes will be cancer-specific survival, recurrence-free survival and overall survival at 5 years from diagnosis. Beyond routine clinicopathological and anthropometric characteristics and laboratory and biochemistry results, the project allows for additional blood samples and fresh-frozen tumour and normal tissue for investigation of circulating tumour cells (CTCs) and novel biomarkers (e.g. immune cells, microRNAs etc.). Tumour specimens will be investigated by immunohistochemistry in full slides. Extracted DNA/RNA will be analysed for genomic markers using specific PCR techniques and next-generation sequencing (NGS) panels. Flow cytometry will be used to characterise biomarkers in blood. Collaboration is open and welcomed, with particular interest in mutual opportunities for validation studies.

Status and perspectives

The project is ongoing and recruiting at an expected rate of 120–150 patients per year, since January 2013. A project on circulating tumour cells (CTCs) has commenced, with analysis being prepared. Investigating molecular classes beyond the TNM staging is under way, including characteristics of microsatellite instability (MSI) and elevated microsatellite alterations in selected tetranucleotides (EMAST). Hot spot panels for known mutations in CRC are being investigated using NGS. Immune-cell characteristics are being performed by IHC and flow cytometry in tumour and peripheral blood samples. The project has ethical approval (REK Helse Vest, #2012/742), is financially supported with a Ph.D.-Grant (EMAST project; Folke Hermansen Cancer Fund) and a CTC-project (Norwegian Research Council; O. Nordgård). The ACROBATICC clinical and molecular biobank repository will serve as a long-term source for novel exploratory analysis and invite collaborators for mutual validation of promising biomarker results. The project aims to generate results that can help better discern prognostic groups in stage II/III cancers; explore prognostic and predictive biomarkers, and help detail the biology of colorectal liver metastasis for better patient selection and tailored treatment. The project is registered at http://www.ClinicalTrials.gov NCT01762813.

The prognostic yield of biomarkers harvested in chemotherapy-naive stage II colon cancer: can we separate the wheat from the chaff?

The TNM-system fails to accurately predict disease recurrence in a considerate number of patients. While node-negative (stage II) colon cancer is considered to have an overall good prognosis, the 5-year cancer-specific survival is reported at 81-83% in patients who did not have adjuvant chemotherapy. Thus, reliance on node-status alone has lead to under-treatment in a subgroup of stage II patients with an unfavorable prognosis. The search for new and better prognosticators in stage II colon cancer has suggested several proposed biomarkers of better prognostication and prediction. However, few such biomarkers have reached widespread clinical utility. For the clinician swimming in the sea of emerging biomarkers, it may be hard to recognize the true floating aid from the surrounding debris in the search for more precise decision-making. Proposed markers include microsatellite instability (MSI), KRAS mutations and BRAF mutations, but a number of gene panels and consensus molecular subtypes are proposed for clinical prediction and prognostication as well. While several studies suggest such biomarkers or panels to have a prognostic role in subgroups of patients, a number of studies are reported in heterogeneous groups with in part discordant findings, which again distorts the predictive and prognostic ability of each marker. Lack of homogeneous cohorts, underpowered studies in strict subgroups and challenges in analytical and clinical validity may hamper the progress towards widespread clinical utility. The harvest of prognostic biomarkers in colon cancer has yielded a huge number of candidates for which it is now time to separate the wheat from the chaff.

Molecular and biological hallmarks of ageing

BACKGROUND

Ageing is the inevitable time-dependent decline in physiological organ function that eventually leads to death. Age is a major risk factor for many of the most common medical conditions, such as cardiovascular disease, cancer, diabetes and Alzheimer's disease. This study reviews currently known hallmarks of ageing and their clinical implications.

METHODS

A literature search of PubMed/MEDLINE was conducted covering the last decade.

RESULTS

Average life expectancy has increased dramatically over the past century and is estimated to increase even further. Maximum longevity, however, appears unchanged, suggesting a universal limitation to the human organism. Understanding the underlying molecular processes of ageing and health decline may suggest interventions that, if used at an early age, can prevent, delay, alleviate or even reverse age-related diseases. Hallmarks of ageing can be grouped into three main categories. The primary hallmarks cause damage to cellular functions: genomic instability, telomere attrition, epigenetic alterations and loss of proteostasis. These are followed by antagonistic responses to such damage: deregulated nutrient sensing, altered mitochondrial function and cellular senescence. Finally, integrative hallmarks are possible culprits of the clinical phenotype (stem cell exhaustion and altered intercellular communication), which ultimately contribute to the clinical effects of ageing as seen in physiological loss of reserve, organ decline and reduced function.

CONCLUSION

The sum of these molecular hallmarks produces the clinical picture of the elderly surgical patient: frailty, sarcopenia, anaemia, poor nutrition and a blunted immune response system. Improved understanding of the ageing processes may give rise to new biomarkers of risk or prognosis, novel treatment targets and translational approaches across disciplines that may improve outcomes.

Elevated microsatellite alterations at selected tetranucleotides in early-stage colorectal cancers with and without high-frequency microsatellite instability: same, same but different?

Microsatellite instability (MSI) is associated with better prognosis in colorectal cancer (CRC). Elevated microsatellite alterations at selected tetranucleotides (EMAST) is a less‐understood form of MSI. Here, we aim to investigate the role of EMAST in CRC±MSI related to clinical and tumor‐specific characteristics. A consecutive, population‐based series of stage I–III colorectal cancers were investigated for MSI and EMAST using PCR primers for 10 microsatellite markers. Of 151 patients included, 33 (21.8%) had MSI and 35 (23.2%) were EMAST+, with an overlap of 77% for positivity, (odds ratio [OR] 61; P < 0.001), and 95% for both markers being negative. EMAST was more prevalent in colon versus rectum (86% vs. 14%, P = 0.004). EMAST+ cancers were significantly more frequent in proximal colon (77 vs. 23%, P = 0.004), had advanced t‐stage (T3–4 vs. T1–2 in 94% vs. 6%, respectively; P = 0.008), were larger (≥5 cm vs. <5 cm in 63% and 37%, respectively; P = 0.022) and had poorly differentiated tumor grade (71 vs. 29%, P < 0.01). Furthermore, EMAST+ tumors had a higher median number of harvested lymph nodes than EMAST− (11 vs. 9 nodes; P = 0.03). No significant association was found between EMAST status and age, gender, presence of distant metastases or metastatic lymph nodes, and overall survival. A nonsignificant difference toward worse survival in node‐negative colon cancers needs confirmation in larger cohorts. EMAST+ cancers overlap and share features with MSI+ in CRC. Overall, survival was not influenced by the presence of EMAST, but may be of importance in subgroups such as node‐negative disease of the colon.

The arthritis knowledge questionnaire. A test for measuring patient knowledge of arthritis and its self-management

OBJECTIVE

To develop a questionnaire for measuring patients' knowledge about arthritis and its self-management.

METHODS

An initial item pool of 175 multiple-choice questions was developed, based on the Stanford Arthritis Self-Management Program and on basic medical knowledge about arthritis and its management. A rheumatologist, psychologist, physiotherapist, and several lay individuals assessed the questions for content validity, breadth of coverage, and face validity. Patients assessed the questions for comprehensibility. Four subject groups with varying knowledge levels were recruited to answer the entire set of questions. Item analysis was undertaken to develop parallel forms of subtests so that repeated assessments could be undertaken.

RESULTS

The final instrument, the Arthritis Knowledge Questionnaire, consists of 2 tests, each comprising 3 subtests: self-management (15 items), arthritis in general (15 items), and rheumatoid arthritis (11 items).

CONCLUSION

We present psychometric evidence that these parallel forms provide highly reliable and valid estimates of knowledge concerning arthritis and arthritis self-management.

Vowel use of phonologically disordered identical twin boys: a case study

Very little is known about the vowel systems of phonologically disordered children. This study provides longitudinal data regarding vowel use of identical twin boys between the ages of 3;5 and 4;9. The boys were identified as phonologically disordered; however, their parents chose not to enroll them in therapy. Vowel-use information was taken from spontaneous language samples. It was discovered that initially their phonological disorder also affected their vowel systems, but as their phonological skills increased so did correct use of vowels and their vowel use tended to follow normal developmental trends.

Consistency of use of phonological processes by a sample of educable mentally impaired children

A group of 10 educable mentally impaired children (M age = 10 yr., 4 mo.) were assessed for use of phonological process under three speaking conditions: production of single words, imitated sentences, and connected speech samples. Only the process of gliding showed significant differences in use among conditions. Results generally indicated that any of those three speaking conditions were viable for eliciting use of phonological processes by such subjects. Results are also discussed in terms of individual differences.

Comparison of three methods for eliciting phonological processes

Eight articulatory disordered children were studied to compare the occurrence of phonological processes using three elicitation methods, including single-word productions, imitated sentences, and continuous speech sampling. A total of 11 phonological processes were shown by the subjects, with only the process of gliding indicative of significantly different rates of occurrence among the three procedures. These subjects were relatively consistent in their use of phonological processes under different speaking conditions.

Referential communication abilities of learning-disabled, language-learning-disabled, and normal school-age children

Past research in referential communication has indicated normally developing children show developmental progression in ability to communicate a specific referent to a listener. In one paradigm subjects were given lists of word-pairs in which one member of each pair was designated as the referent. It was shown that communicating about referents found in word-pairs associated in some way was more difficult than communicating about referents in dissimilar word-pairs. The present study extended this methodology to learning-disabled children. Learning-disabled, language-learning-disabled, and normally achieving children were asked to communicate about 30 pictured referents on three different tasks. On Tasks 1 and 2 each subject was asked to give a clue for the referent that would distinguish it from the other picture. Stimuli for Task 1 were 30 pairs of pictures that were related in some way and the stimuli for Task 2 were 30 pairs of unrelated pictures. Task 3 required the subjects to evaluate the adequacy of the examiner's clues for Task 1 stimuli. The disabled subjects were matched to the normally achieving subjects on the basis of receptive vocabulary age. Few differences were noted among the groups' performances on these referential communication tasks. Implications include the importance of vocabulary and concept development to referential communication.

Time compression and spectral characteristics of phonemes

The present study compared spectral characteristics of the test phonemes of Subtest 13 of Auditory-Visual Abilities Test produced at a normal rate and a 50% time-compression. Results showed marked damping of high frequency energy above 3000 Hz, a by-product of the instrumentation.

The effects of time compression on the auditory processing abilities of learning disabled children

This study measured the ability of ten 8- and ten 12-yr-old learning disabled (LD) children of normal intelligence (WISC-R) to discriminate phonemic contrasts in sentential stimuli (Subtest 13 of the Carrow Auditory Visual Abilities Test) presented at a 50% time-compression rate. Their group responses were compared statistically to similar data gathered earlier (May et al, J. Aud. Res., 1984, 24, 205-211) from 6-, 8-, and 10-yr-old normal children and young adults. LD Ss exhibited auditory processing capacities reminiscent of an earlier level of operation (e.g., the group of LD Ss with mn age of 12.8 yrs yielded group performance equivalent to that of normal 6- and 8-yr-olds), and also manifested marked differences in their feature- and frequency-processing abilities. These data indicate that contributing to the learning difficulties of LD children may very well be delays in auditory development and anomalies in auditory-feature processing.