CK19 mRNA in blood can predict non-sentinel lymph node metastasis in breast cancer

Methods for Collection of Extracellular Vesicles and Their Content RNA as Liquid Biopsy for Lung Cancer Detection: Application of Differential Centrifugation and Annexin A5 Coated Beads

Extracellular vesicles (EVs) contain abundant extracellular RNA (exRNA), which can be a valuable source of liquid biopsy. However, as various RNA species exist in different types of EVs, lack of detailed characterization of these RNA species and efficient collection methods limits the clinical application of exRNA. In the present study, we measured two mRNAs, CK19 and PCTK1; one lncRNA, MALAT1; and two miRNAs, miR21 and miR155, in different EV fractions separated by differential centrifugation or captured by magnetic beads coated with annexin A5 (ANX beads). The results showed that in a cultured medium, the majority of mRNA and lncRNA exist in larger EVs, whereas miRNA exist in both large and small EVs from the differential centrifugation fractions. All these RNA species exist in ANX beads captured EVs. We then used ANX beads to capture EVs in plasma samples from non-small-cell lung cancer patients and age-matched healthy volunteers. We found that the ANX bead capturing could efficiently improve RNA detection from human plasma, compared with direct extraction of RNA from plasma. Using ANX-bead capturing and reverse transcription and quantitative PCR, we detected significantly higher levels of CK19 mRNA, MALAT1 lncRNA, and miR155 miRNA in the plasma of lung cancer patients. These facts suggested the collection methods strongly affect the results of exRNA measurement from EVs, and that ANX beads can be a useful tool for detecting exRNA from plasma samples in clinical application.

Keratin 19 maintains E-cadherin localization at the cell surface and stabilizes cell-cell adhesion of MCF7 cells

A cytoskeletal protein keratin 19 (K19) is highly expressed in breast cancer but its effects on breast cancer cell mechanics are unclear. In MCF7 cells where K19 expression is ablated,we found that K19 is required to maintain rounded epithelial-like shape and tight cell-cell adhesion. A loss of K19 also lowered cell surface E-cadherin levels. Inhibiting internalization restored cell-cell adhesion of KRT19  knockout cells, suggesting that E-cadherin internalization contributed to defective adhesion. Ultimately, while K19 inhibited cell migration and invasion, it was required for cells to form colonies in suspension. Our results suggest that K19 stabilizes E-cadherin complexes at the cell membrane to maintain cell-cell adhesion which inhibits cell invasiveness but provides growth and survival advantages for circulating tumor cells.

A Prospective Validation Cohort Study of a Prediction Model on Non-sentinel Lymph Node Involvement in Early Breast Cancer

BACKGROUND

Early breast cancer with one or two sentinel lymph nodes (SLNs) may omit axillary lymph node dissection (ALND) if followed by radiotherapy. However, only less than one-third of the patients have positive non-SLNs and can truly benefit from radiotherapy. Before any regional treatment decision, the risk of non-SLN metastasis must be identified. The authors previously developed a predictive model for non-SLN involvement using CK19 mRNA and contrast-enhanced ultrasound (CEUS) score in a training set. They designed a further study to evaluate the predictive effect using the model prospectively in a validation set of one or two involved SLNs.

METHODS

This study identified early breast cancer patients at Zhejiang Cancer Hospital from July 2017 to June 2018. The CK19 mRNA tested by quantitative real-time polymerase chain reaction and CEUS scores were collected before surgery. Patients with one or two involved SLNs were enrolled and underwent ALND. The estimated percentage of non-SLN involvement was calculated by the authors' model formula and the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram. The false-negative rates, predictive accuracy, and area under curve (AUC) were compared between two predictive models.

RESULTS

The study enrolled 235 patients, and 35.36% (83/235) of them had non-SLN involvement. The authors' model had a false-negative rate of 6% and an accuracy of 94.9%. The AUC was 0.952 (95% confidence interval [CI] 0.922-0.982), which was significantly higher than that of the MSKCC model at all three cutoff value levels.

CONCLUSION

The authors' model, using CK19 mRNA and the CEUS score, showed the potential predictive value of non-SLNs before surgery for early breast cancer patients.

CLINICALTRIALS REGISTRY

NCT02992067, NCT03280134.

KRT19 and CEACAM5 mRNA-marked circulated tumor cells indicate unfavorable prognosis of breast cancer patients

AIM

To investigate the clinical and prognostic significance of circulated tumor cells (CTC) marked by cytokeratin 19 coding gene KRT19 mRNA and carcinoembryonic antigen coding gene CEACAM5 mRNA in preoperative peripheral blood of breast cancer patients and provide molecular markers for breast cancer metastasis risk.

METHODS

The mRNA levels of KRT19 and CEACAM5 in preoperative peripheral blood of breast cancer patients without (n = 603) and with (n = 76) distant metastases at the time of initial diagnosis were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The relationship between CTC_KRT19, CTC_CEACAM5 and clinicopathological features, local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), or overall survival (OS) was statistically analyzed.

RESULTS

In different pathological stages of breast cancer, the rates of CTC_KRT19-pos and CTC_CEACAM5-pos increased with the increase of the stages (P = 0.077 and P = 0.004). Preoperative CTC_KRT19-pos in breast cancer patients was closely related to the lymph node metastasis statues (P < 0.0001), and had no significant correlation with other clinicopathological features. There was no significant correlation between CTC_CEACAM5 and the clinicopathological features. Patients with high levels of CTC double-marked by KRT19 and CEACAM5 mRNA had shorter DMFS (P < 0.0001) and OS (P = 0.016) for patients with breast cancer. The 7-year DMFS rates for the low-, intermediate-, and high-risk groups were 90.7%, 67.5%, and 59.1%, respectively (P < 0.0001). The prognosis of patients with decreased KRT19 and CEACAM5 mRNA after treatment is better than that of patients who have not decreased, and the combination of the two indicators is better than the single one for predicting PFS (P = 0.002 compare with P = 0.036 or P = 0.047).

CONCLUSION

Double-marked CTC by KRT19 and CEACAM5 mRNA is a prognostic index of breast cancer patients before surgery and after chemotherapy. Single-marked CTC by KRT19 mRNA indicates lymph node statues of preoperative patients. Therefore, the RT-qPCR-based molecular diagnosis of CTC could be used for prognostic prediction of breast cancer patients and guiding clinical treatment.

Expression of CK19, CD105 and CD146 are associated with early metastasis in patients with renal cell carcinoma

The present study was designed in order to explore the association between the early metastasis of renal cell carcinoma (RCC) and biological markers of tumor cells. A total of 200 patients with RCC, who received a nephrectomy between January 2015 and October 2015, were enrolled in the present study, while 100 healthy patients served as controls. The expression of cytokeratin 19 (CK19), endoglin (CD105) and cluster of differentiation 146 (CD146) were detected using immunohistochemical staining and western blotting. All three markers were highly expressed in tumor tissues compared with adjacent normal tissues. Subsequently, an enzyme-linked immunosorbent assay was used to detect the differential expression of CK19, CD105 and CD146. The results revealed that there was a statistically significant difference in the expression of CK19 and CD105 between the two groups (P<0.05), whereas CD146 did not exhibit a statistically significant difference. The results of further experiments revealed no significant difference between four time points (Q1, 1 day pre-operation; Q2, 1 day post-operation; Q3, 1 week post-operation; and Q4, 1 month post-operation). Then, subgroup analysis was performed based on whether patients were circulating tumor cell (CTC)-positive or not, and the difference between the Q1 time point and other three time points (Q2-4). The results revealed no difference between the CTC-positive and -negative groups, and no difference between the time points Q1 and Q2. However, the expression of CK19 and CD105 exhibited a significant difference between CTC-positive and CTC-negative groups according to the difference between the time points Q1 and Q3. Furthermore, on the basis of the difference between Q1 and Q4, the expression of CK19, CD105 and CD146 were significantly different (P<0.05). Taken together, the results suggested that CK19, CD105 and CD146 markers of peripheral blood may be considered to be effective tools to evaluate the early metastasis in a CTC-positive condition. CK19, CD105 and CD146 may be useful for CTC in evaluating the prognosis of patients with RCC, although a larger sample size is necessary for further investigation.