Advancing canine mammary tumor diagnostics: Unraveling the diagnostic potential of Cytokeratin 19 through droplet digital PCR analysis.

Cytokeratin 19 (CK19) is a complex intracytoplasmic cytoskeletal protein primarily localized in the ducts of the mammary gland and skin epithelial cells. In humans, the expression of CK19 gene within circulating tumor cells (CTCs) extracted from blood samples of breast cancer patients reflects tumor cell activity, offering valuable insights for predicting early metastatic relapse or monitoring treatment effectiveness. However, knowledge of serum tumor markers is limited in veterinary oncology. Recently, droplet digital PCR (ddPCR), has been employed to explore rare target genes due to its heightened sensitivity and accuracy as a novel molecular diagnostic tool. The objectives of this study were to investigate the expression of the CK19 mRNA in CTCs, non-neoplastic mammary tissues, and both benign and malignant canine mammary tumors (CMTs) through ddPCR analysis. In Study I, we optimized the discard volume for blood samples to reduce CK19 contamination from skin epithelial cells post-venipuncture. The results revealed that discarding the initial 3 mL of blood was adequate and effective in eliminating CK19 mRNA contamination. In Study II, after the removal of the initial 3 mL of blood, we investigated CK19 mRNA-positive CTCs in the peripheral blood of normal healthy dogs, including those with benign and malignant CMTs. Intriguingly, CK19 mRNA was undetectable in all blood samples. The expression of CK19 mRNA in mammary tissues was investigated in Study III. The copy number (CN) ratios of the CK19 gene in non-neoplastic mammary tissues (14.77 ± 14.65) were significantly higher (P < 0.05) than those in benign (4.23 ± 3.35) and malignant groups (6.56 ± 5.64). Notably, no difference was observed between the benign and malignant groups. In conclusion, CK19 mRNA appeared unlikely to be a suitable candidate as a biomarker in the peripheral blood of CMTs, while the CN ratio in mammary tissues could serve as a potential discriminator between non-neoplastic and CMT groups, complementing the gold standard of histopathological examination.

Integrating single-cell and bulk RNA sequencing reveals CK19 + cancer stem cells and their specific SPP1 + tumor-associated macrophage niche in HBV-related hepatocellular carcinoma.

PURPOSE: Cytokeratin 19-positive cancer stem cells (CK19 + CSCs) and their tumor-associated macrophages (TAMs) have not been fully explored yet in the hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: Single-cell RNA sequencing was performed on the viable cells obtained from 11 treatment-naïve HBV-associated HCC patients, including 8 CK19 + patients, to elucidate their transcriptomic landscape, CK19 + CSC heterogeneity, and immune microenvironment. Two in-house primary HCC cohorts (96 cases-related HBV and 89 cases with recurrence), TCGA external cohort, and in vitro and in vivo experiments were used to validate the results. RESULTS: A total of 64,581 single cells derived from the human HCC and adjacent normal tissues were sequenced, and 11 cell types were identified. The result showed that CK19 + CSCs were phenotypically and transcriptionally heterogeneous, co-expressed multiple hepatics CSC markers, and were positively correlated with worse prognosis. Moreover, the SPP1 + TAMs (TAM_SPP1) with strong M2-like features and worse prognosis were specifically enriched in the CK19 + HCC and promoted tumor invasion and metastasis by activating angiogenesis. Importantly, matrix metalloproteinase 9 (MMP9) derived from TAM_SPP1, as the hub gene of CK19 + HCC, was activated by the VEGFA signal. CONCLUSIONS: This study revealed the heterogeneity and stemness characteristics of CK19 + CSCs and specific immunosuppressive TAM_SPP1 in CK19 + HCC. The VEGFA signal can activate TAM_SPP1-derived MMP9 to promote the invasion and metastasis of CK19 + HCC tumors. This might provide novel insights into the clinical treatment of HCC patients.

A radiomics model based on magnetic resonance imaging to predict cytokeratin 7/19 expression and liver fluke infection of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. HCC with liver fluke infection could harbor unique biological behaviors. This study was aimed at investigating radiomics features of HCC with liver fluke infection and establishing a model to predict the expression of cytokeratin 7 (CK7) and cytokeratin 19 (CK19) as well as prognosis at the same time. A total of 134 HCC patients were included. Gadoxetic acid-enhanced magnetic resonance imaging (MRI) images of all patients were acquired. Radiomics features of the tumor were extracted and then data dimensionality was reduced. The radiomics model was established to predict liver fluke infection and the radiomics score (Radscore) was calculated. There were 11 features in the four-phase combined model. The efficiency of the combined model increased significantly compared to each single-phase MRI model. Radscore was an independent predictor of liver fluke infection. It was also significantly different between different expression of CK7/ CK19. Meanwhile, liver fluke infection was associated with CK7/CK19 expression. A cut-off value was set up and all patients were divided into high risk and low risk groups of CK7/CK19 positive expression. Radscore was also an independent predictor of these two biomarkers. Overall survival (OS) and recurrence free survival (RFS) of negative liver fluke infection group were significantly better than the positive group. OS and RFS of negative CK7 and CK19 expression were also better, though not significantly. Positive liver fluke infection and CK19 expression prediction groups harbored significantly worse OS and RFS, survival of positive CK7 expression prediction was unsatisfying as well. A radiomics model was established to predict liver fluke infection among HCC patients. This model could also predict CK7 and CK19 expression. OS and RFS could be foreseen by this model at the same time.

DNA methylation-associated allelic inactivation regulates Keratin 19 gene expression during pancreatic development and carcinogenesis.

Within the pancreas, Keratin 19 (KRT19) labels the ductal lineage and is a determinant of pancreatic ductal adenocarcinoma (PDAC). To investigate KRT19 expression dynamics, we developed a human pluripotent stem cell (PSC)-based KRT19-mCherry reporter system in different genetic backgrounds to monitor KRT19 expression from its endogenous gene locus. A differentiation protocol to generate mature pancreatic duct-like organoids was applied. While KRT19/mCherry expression became evident at the early endoderm stage, mCherry signal was present in nearly all cells at the pancreatic endoderm (PE) and pancreatic progenitor (PP) stages. Interestingly, despite homogenous KRT19 expression, mCherry positivity dropped to 50% after ductal maturation, indicating a permanent switch from biallelic to monoallelic expression. DNA methylation profiling separated the distinct differentiation intermediates, with site-specific DNA methylation patterns occurring at the KRT19 locus during ductal maturation. Accordingly, the monoallelic switch was partially reverted upon treatment with a DNA-methyltransferase inhibitor. In human PDAC cohorts, high KRT19 levels correlate with low locus methylation and decreased survival. At the same time, activation of oncogenic KRASG12D signalling in our reporter system reversed monoallelic back to biallelic KRT19 expression in pancreatic duct-like organoids. Allelic reactivation was also detected in single-cell transcriptomes of human PDACs, which further revealed a positive correlation between KRT19 and KRAS expression. Accordingly, KRAS mutant PDACs had higher KRT19 mRNA but lower KRT19 gene locus DNA methylation than wildtype counterparts. KRT19 protein was additionally detected in plasma of PDAC patients, with higher concentrations correlating with shorter progression-free survival in gemcitabine/nabPaclitaxel-treated and opposing trends in FOLFIRINOX-treated patients. Apart from being an important pancreatic ductal lineage marker, KRT19 appears tightly controlled via a switch from biallelic to monoallelic expression during ductal lineage entry and is aberrantly expressed after oncogenic KRASG12D expression, indicating a role in PDAC development and malignancy. Soluble KRT19 might serve as a relevant biomarker to stratify treatment. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Cytokeratin 19 (CK19) expression by thyroid neoplasms in a Nigerian tertiary health centre.

Introduction: despite the observed appreciable sensitivity and specificity of the use of CK19 in predicting thyroid malignancies, there is still a paucity of information about its uses in Nigeria. Current information across the world is also scarce. This study was to review the histopathological diagnosis of thyroid neoplasms seen in Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile Ife, using cytokeratin 19 immunohistochemical marker. Methods: a retrospective study of fifty-six cases of thyroid neoplasm seen over a period of twenty years was conducted. The tissue samples were subjected to immunohistochemical staining for CK19 using monoclonal antibodies. The expression of the markers on the various thyroid neoplasms was assessed histologically. Results: the expression of CK19 was significantly higher in malignant thyroid neoplasms compared to benign neoplasms (p<0.05). The sensitivity and specificity for cytokeratin 19 were 90.0% and 75.0% respectively. Conclusion: diffuse immunohistochemical expression of CK19 is a strong indicator of thyroid malignancy. This biomarker can help in the diagnosis of thyroid neoplasms especially those with incomplete or equivocal histomorphology features.

SOX9 Expression Is Superior to Other Stem Cell Markers K19 and EpCAM in Predicting Prognosis in Hepatocellular Carcinoma.

Various stem cell markers (eg, epithelial cell adhesion molecule [EpCAM], cytokeratin 19 [K19]) have been reported as predictors of poor prognosis in hepatocellular carcinoma (HCC). However, the data remain limited, particularly in Western populations, and are often contradictory. In this study, the prognostic value of positive SOX9 immunohistochemistry was compared with that of more established markers EpCAM and K19 in a large cohort (n=216) of North American patients. The independent HCC cohort in The Cancer Gene Atlas (n=360) was utilized to validate our findings. Finally, molecular signatures associated with SOX9 -high HCC were determined. We found that the expression of SOX9, but not EpCAM or K19, was associated with worse overall survival and disease-free survival (DFS) and was an independent prognostic factor for DFS in our North American cohort, in which hepatitis C infection was the most common underlying etiology. High SOX9 mRNA level, but not increased expression of EpCAM mRNA or K19 mRNA, was also associated with worse DFS and was an independent prognostic factor for DFS in The Cancer Gene Atlas cohort. This group had underlying causes, including an increased incidence of hepatitis B, significantly different from our initial cohort. High SOX9 mRNA level is associated with molecular pathways important in HCC pathogenesis. Increased SOX9 expression is clinically and biologically relevant for HCC arising in patients with a variety of underlying etiologies. Immunohistochemistry for SOX9 is a reliable proxy for increased SOX9 mRNA and can be used to predict prognosis in HCC cases.

Molecular Characteristics and Immunogenomic Profiling of Cholangioblastic Variant of Intrahepatic Cholangiocarcinoma in a 68-year-old Patient.

BACKGROUND/AIM: Cholangioblastic variant of intrahepatic cholangiocarcinoma (CVICC) is an exceedingly rare primary biliary tract tumor and typically occurs in young patients with a median age of 24.5-year-old. It can mimic metastatic well-differentiated neuroendocrine tumors in the liver with its similar histologic and immunophenotypic features. CASE REPORT: We hereby report a CVICC in a 68-year-old female patient with distinctive biphasic cytologic features. The patient was diagnosed and treated as a metastatic well differentiated neuroendocrine tumor. The recurrent liver tumor was resected and the tumor cells were strongly positive for Inhibin A and cytokeratin 19 (CK19), focally and weakly positive for synaptophysin and chromogranin, and negative for Insulinoma associated protein 1 (INSM1). Ribonucleic acid (RNA) sequencing showed that the tumor bared a characteristic Nipped-B-like protein (NIPBL)-Nucleus accumbens-associated protein 1 (NACC1) gene fusion. CONCLUSION: To the best of our knowledge, this is the first documented case in an elder patient of this entity with NIPPL-NACC1 gene fusion. Acknowledgment of the biphasic cytology, screening with Inhibin A in suspicious cases, and coupled with a molecular study may facilitate accurate classification of this aggressive tumor and lead to proper clinical management.

The Group B Streptococcal Adhesin BspC Interacts with Host Cytokeratin 19 To Promote Colonization of the Female Reproductive Tract.

Streptococcus agalactiae, otherwise known as Group B Streptococcus (GBS), is an opportunistic pathogen that vaginally colonizes approximately one third of healthy women. During pregnancy, this can lead to in utero infection, resulting in premature rupture of membranes, chorioamnionitis, and stillbirths. Furthermore, GBS causes serious infection in newborns, including sepsis, pneumonia, and meningitis. Previous studies have indicated that GBS antigen (Ag) I/II family proteins promote interaction with vaginal epithelial cells; thus, we hypothesized that the Ag I/II Group B streptococcal surface protein C (BspC) contributes to GBS colonization of the female reproductive tract (FRT). Here, we show that a ΔbspC mutant has decreased bacterial adherence to vaginal, ecto-, and endocervical cells, as well as decreased auto-aggregation and biofilm-like formation on cell monolayers. Using a murine model of vaginal colonization, we observed that the ΔbspC mutant strain exhibited a significant fitness defect compared to wild-type (WT) GBS and was less able to ascend to the cervix and uterus in vivo, resulting in reduced neutrophil chemokine signaling. Furthermore, we determined that BspC interacts directly with the host intermediate filament protein cytokeratin 19 (K19). Surface localization of K19 was increased during GBS infection, and interaction was mediated by the BspC variable (V) domain. Finally, mice treated with a drug that targets the BspC V-domain exhibited reduced bacterial loads in the vaginal lumen and reproductive tissues. These results demonstrate the importance of BspC in promoting GBS colonization of the FRT and that it may be targeted therapeutically to reduce GBS vaginal persistence and ascending infection. IMPORTANCE Group B Streptococcus (GBS) asymptomatically colonizes the female reproductive tract (FRT) of up to one third of women, but GBS carriage can lead to adverse pregnancy outcomes, including premature rupture of membranes, preterm labor, and chorioamnionitis. GBS colonization during pregnancy is also the largest predisposing factor for neonatal GBS disease, including pneumonia, sepsis, and meningitis. The molecular interactions between bacterial surface proteins and the host cell receptors that promote GBS colonization are vastly understudied, and a better understanding would facilitate development of novel therapeutics to prevent GBS colonization and disease. Here, we characterize the role of the GBS surface protein BspC in colonization of the FRT. We show for the first time that GBS infection induces cytokeratin 19 (K19) surface localization on vaginal epithelial cells; GBS then uses the BspC V-domain to interact with K19 to promote colonization and ascending infection. Furthermore, this interaction can be targeted therapeutically to reduce GBS carriage.

Diagnostic utility of CK19 and galectin-3 in differentiating papillary thyroid carcinoma from nonneoplastic lesions of thyroid.

Background: Thyroid neoplasm is one of the most common endocrine neoplasms. The diagnosis and the distinction between malignant and benign neoplasms can be difficult, but it has clinical, therapeutic, and prognostic significance. Hence, it is necessary to make precise diagnosis by using biomarkers. Materials and Methods: This is a laboratory observational study considering histologically diagnosed cases of papillary thyroid carcinoma (PTC) and nonneoplastic thyroid lesions. Immunohistochemistry (IHC) staining was done on tissue sections of all cases for CK19 and galectin-3 using appropriate positive and negative controls. The expression of immunomarkers was evaluated by a semi-quantitative method as negative, weak positive, moderate positive, and strong positive. The data were entered in Microsoft Excel sheet and were analyzed using SPSS 22 version software. Results: A total of 52 cases were considered for the study, of which 26 cases each were PTC and nonneoplastic lesions of thyroid. Among the 26 PTC cases, 6 were classical variant of PTC (CVPTC) and 20 were follicular variant of papillary thyroid carcinoma (FVPTC). Among 26 nonneoplastic cases, 13 each were nodular hyperplasia cases and lymphocytic thyroiditis. There was a statistically significant (P < 0.01) association of CK19 and galectin-3 expression between CVPTC and FVPTC. There was no statistically significant association (P = 0.271) of CK19 expression between PTC and nonneoplastic cases. There was a statistically significant association (P = 0.003) of galectin-3 expression between PTC and nonneoplastic cases. Conclusion: Galectin-3 expression can be used to differentiate PTC from nonneoplastic lesions of thyroid in ambiguous cases. Galectin-3 and CK19 expression can be used to classify PTC into CVPTC and FVPTC.

Evaluation of CK19 and VEGF gene expression, ki67 antigen, p53 protein, C-erb-B2, and their relationship in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is one of the ten most common malignant tumors globally. This study aimed to evaluate the expression changes of Cytokeratin 19 (CK19), vascular endothelial growth factor (VEGF), P53, ki67, and c-ert-B2 in OSCC patients. For this purpose, 30 patients were selected as the case group and 30 healthy individuals as the control group. The expression of CK19 and VEGF genes in their blood serum was measured. Also, the expression of ki67, P53, and c-ert-B2 markers in squamous cell carcinoma was evaluated using immunohistochemistry. T-test was used to analyze the data. The results showed that the presence of CK19 marker in people with OSCC was positive in 17 out of 30 patients and VEGF marker in 23 out of 30 patients. The mean of ki67 positive, P53 positive, and Cerb-B2 positive cells were 399.4, 221.4, and 26.8, respectively. The correlation test between the indices showed a statistical correlation between the incidence of ki67 and P53 (r = 91.5% and p = 0.02). While statistical correlation was not seen between the incidence of ki67 and Cerb-B2 index (r = -1.7% and p = 0.97) and P53 and C-erb-B2 index (r = -13% and p = 0.8) (p <0.05). In general, the expression of VEGF and CK19 genes is higher in patients with OSCC than in healthy individuals. Therefore, examining the expression level of these two biomarkers in the blood of OSCC patients can be considered as a diagnostic screening method in the early stages of the disease. The immunohistochemical study of squamous cell carcinoma can also be used as a diagnostic screening test in the early stages of the disease.

Individual and joint influence of cytokeratin 19 and microvascular invasion on the prognosis of patients with hepatocellular carcinoma after hepatectomy.

BACKGROUND AND OBJECTIVES: To evaluate the individual and combined associations of cytokeratin 19 (CK19) and microvascular invasion (MVI) with prognosis of patients with hepatocellular carcinoma (HCC). METHODS: Clinicopathological data on 352 patients with HCC who underwent radical resection at our hospital between January 2013 and December 2015 were retrospectively analyzed. Patients were divided into four groups: CK19(-)/MVI(-), CK19(-)/MVI(+), CK19(+)/MVI(-), and CK19(+)/MVI(+). RESULTS: Of the 352 HCC patients, 154 (43.8%) were CK19(-)/MVI(-); 116 (33.0%), CK19(-)/MVI(+); 31 (8.8%), CK19(+)/MVI(-); and 51 (14.5%), CK19(+)/MVI(+). The disease-free survival of CK19(-)/MVI(-) patients was significantly higher than that of CK19(-)/MVI(+) patients and CK19(+)/MVI(+) patients. Similar results were observed for overall survival. CK19(+)/MVI(+) patients showed significantly lower overall survival than the other three groups. CONCLUSIONS: CK19 expression and MVI predict poor prognosis after radical resection of HCC, and the two markers jointly contribute to poor OS. Combining CK19 and MVI may predict post-resection prognosis better than using either factor on its own.

Differentiating Cytokeratin 19 expression of hepatocellular carcinoma by using multi-b-value diffusion-weighted MR imaging with mono-exponential, stretched exponential, intravoxel incoherent motion, diffusion kurtosis imaging and fractional order calculus models.

PURPOSE: To evaluate Cytokeratin 19 expression in hepatocellular carcinoma (HCC) with diffusion parameters derived from mono-exponential model (MEM), stretched exponential model (SEM), diffusion kurtosis imaging (DKI), intravoxel incoherent motion (IVIM) imaging, and fractional order calculus (FROC) model and compare their predictive performance. METHOD: 61 patients with pathologically confirmed primary HCC were included in this prospective study. All the DWIs were acquired using a 3.0 T MR scanner with 10b-values (0-2000 s/mm2). The apparent diffusion coefficient (ADC), distributed diffusion coefficient (DDC), heterogeneity index (α), apparent kurtosis coefficient (AK), apparent diffusion coefficient (AD), pseudo-diffusion coefficient (Dp), true diffusion coefficient (Dt), perfusion fraction (f), diffusion coefficient (D), fractional order parameter (ß), and a microstructural quantity (µ) were calculated. The diagnostic efficacy of various diffusion parameters for predicting CK19 expression of HCC was compared. RESULTS: ADC, DDC, Dt, Dp, AD, and D were significantly lower in CK19-positive HCCs than in CK19-negative HCCs (P ≤ 0.05). ß was significantly higher in CK19-positive group (P = 0.001). AD (AUC = 0.845) had the greatest AUC values in differentiating CK19-positive and CK19-negative HCC with individual parameters. The combination of ß, AD, and Dp generated the highest area under the ROC curve (AUC = 0.881) compared with individual parameters. CONCLUSIONS: ADC, DDC, Dt, Dp, D, and ß may serve as noninvasive and quantitative imaging markers and holds great potential in accurately accessing CK19 status of HCC. More importantly, the combination of different diffusion parameters yielded better diagnostic performance.

A preliminary study on the detection of lymph node metastasis in cervical cancer using a quantitative RT-PCR assay.

OBJECTIVE: This preliminary study aimed to assess the detection accuracy of sentinel lymph node metastasis in cervical cancer using quantitative reverse transcriptase-polymerase chain reaction. METHODS: We collected cervical cancer tissues and 70 pelvic lymph node samples from patients with cervical cancer. The quantitative reverse transcriptase-polymerase chain reaction assay was performed to investigate the expression of cytokeratin 19 mRNA in cervical cancer tissues and determine the cutoff value of cytokeratin 19 mRNA between the non-metastatic and metastatic lymph nodes. RESULTS: The expression of cytokeratin 19 mRNA in cancer tissues was detected in all (71/71) the tumours, with a median copy number of 7.56 × 105/µl of RNA by quantitative reverse transcriptase-polymerase chain reaction. Sixteen lymph nodes were diagnosed as positive by pathological examination. The median copy numbers of cytokeratin 19 mRNA for positive and negative lymph nodes were 43.3 × 104/µl and 121.1/µl, respectively. The expression of cytokeratin 19 mRNA in pathologically positive lymph nodes was higher than that in the negative lymph nodes (P < 0.0001) by quantitative reverse transcriptase-polymerase chain reaction analysis. Using a receiver operating characteristic plot, the maximum sensitivity (100%) and specificity (94.4%) were obtained when the cutoff value was set at 1169 copies/µl. CONCLUSIONS: After setting the cutoff value at 1169 copies/µl, a quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA showed high accuracy in detecting lymph node metastasis in cervical cancer. We believe that the quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA may be acceptable for lymph node metastasis detection in patients with cervical cancer.

Inhibition of the extracellular signal-regulated kinase pathway reduces the inflammatory component in nucleus pulposus cells.

Intervertebral disc (IVD) degeneration is a spinal disorder that triggers an inflammatory response and subsequent development of spinal pseudoarthrosis. The aim of the present study is to elucidate the role of the extracellular signal-regulated kinase (ERK) pathway in inflammation-induced IVD cells. Inflammatory human nucleus pulposus (NP) cells (NPCs) were induced using tumor necrosis factor-α and the ERK pathway was blocked using a selective molecule-based inhibitor U0126. Gene expression of catabolic and anabolic markers, proinflammatory, and NPCs markers was investigated. The enzymatic activity of matrix metalloproteinases (MMP)2/MMP9 was determined by gelatin zymography and nitrite production was assessed by Griess reaction. The NPC metabolic activity and viability were assessed using resazurin sodium-salt and live/dead assays, and subsequently, the specificity of U0126 on ERK1/2 signaling was determined. The catabolic enzyme MMP3 (p = 0.0001) and proinflammatory cytokine interleukin 6 (p = 0.036) were downregulated by U0126 in NPCs under inflammatory conditions. A significant increase of the cytokeratin 19 (p = 0.0031) was observed, suggesting a partial and possible recovery of the NP phenotype. U0126 does not seem to have an effect on prostaglandin production, aggrecanases, or other anabolic genes. We confirmed that U0126 selectively blocks the ERK phosphorylation and only affects the cell metabolic activity without the reduction of viable cells. Inhibition of ERK signaling downregulates important metalloproteinases and proinflammatory cytokines, and upregulates some NP markers, suggesting its potential to treat IVD degeneration.

Cytokeratin 19 expression in intrathoracic neoplasms: First study utilizing cellblocks, evaluating the role of a rarely used cytokeratin for lung cancers.

BACKGROUND: Cytokeratin 19 (CK19) is low-molecular weight CK with widespread expression in various malignancies including those of lung, colon, and breast. Occasional studies have also indicated prognostic utility of CK19 in nonsmall cell lung carcinomas, with better prognosis among squamous cell carcinoma cases with strong CK19 immunostaining. The aim of this study was to evaluate the expression and potential roles of CK19 immunostaining in cases of carcinoma lung as well as other metastatic intrathoracic neoplasms. METHODS: This was a prospective single-center study of 2 years duration, during which 233 cases of endobronchial ultrasound guided aspiration of the intrathoracic lesions were examined. After excluding the cases without cellblock, with inadequate samples, with benign diagnosis, and excluding the lymphoma cases, finally 31 neoplastic cases were evaluated for expression of cytokeratin 19. RESULTS: Diffuse cytoplasmic staining for CK19 was noted in nonsmall cell lung carcinomas (18/19 cases), while the expression in small cell carcinomas was low (2/5 cases). CK19 was also positive in mediastinal lymph node metastasis from a case each of papillary thyroid carcinoma, prostatic adenocarcinoma and infiltrating ductal carcinoma breast (1/2 cases). It showed focal faint staining in a case of mediastinal mesenchymal neoplasm and was negative in both the cases of primitive neuroectodermal tumor. CONCLUSIONS: CK19 is a highly sensitive but nonspecific marker for nonsmall cell lung cancers. However, owing to diffuse staining pattern in most of these cases, role of its staining intensity as a predictor of prognosis could not be evaluated.

Deletion of kif3a in CK19 positive cells leads to primary cilia loss, biliary cell proliferation and cystic liver lesions in TAA-treated mice.

BACKGROUND & AIMS: Loss of primary cilia in epithelial cells is known to cause cystic diseases of the liver and kidney. We have previously shown that during experimental and human cirrhosis that primary cilia were predominantly expressed on biliary cells in the ductular reaction. However, the role of primary cilia in the pathogenesis of the ductular reaction is not fully understood. METHODS: Primary cilia were specifically removed in biliary epithelial cells (BECs) by the administration of tamoxifen to Kif3af/f;CK19CreERT mice at week 2 of a 20-week course of TAA treatment. Biliary progenitor cells were isolated and grown as organoids from gallbladders. Cells and tissue were analysed using histology, immunohistochemistry and Western blot assays. RESULTS: At the end of 20 weeks TAA administration, primary cilia loss in liver BECs resulted in multiple microscopic cystic lesions within an unaltered ductular reaction. These were not seen in control mice who did not receive TAA. There was no effect of biliary primary cilia loss on the development of cirrhosis. Increased cellular proliferation was seen within the cystic structures associated with a decrease in hepatocyte lobular proliferation. Loss of primary cilia within biliary organoids was initially associated with reduced cell passage survival but this inhibitory effect was diminished in later passages. ERK but not WNT signalling was enhanced in primary cilia loss-induced cystic lesions in vivo and its inhibition reduced the expansion of primary cilia deficient biliary progenitor cells in vitro. CONCLUSIONS: TAA-treated kif3a BEC-specific knockout mice had an unaltered progression to cirrhosis, but developed cystic lesions that showed increased proliferation.

Carcinomas assemble a filamentous CXCL12-keratin-19 coating that suppresses T cell-mediated immune attack.

Cancer immunotherapy frequently fails because most carcinomas have few T cells, suggesting that cancers can suppress T cell infiltration. Here, we show that cancer cells of human pancreatic ductal adenocarcinoma (PDA), colorectal cancer, and breast cancer are coated with transglutaminase-2 (TGM2)-dependent covalent CXCL12-keratin-19 (KRT19) heterodimers that are organized as filamentous networks. Since a dimeric form of CXCL12 suppresses the motility of human T cells, we determined whether this polymeric CXCL12-KRT19 coating mediated T cell exclusion. Mouse tumors containing control PDA cells exhibited the CXCL12-KRT19 coating, excluded T cells, and did not respond to treatment with anti-PD-1 antibody. Tumors containing PDA cells not expressing either KRT19 or TGM2 lacked the CXCL12-KRT19 coating, were infiltrated with activated CD8+ T cells, and growth was suppressed with anti-PD-1 antibody treatment. Thus, carcinomas assemble a CXCL12-KRT19 coating to evade cancer immune attack.

Clinical Impact of CYFRA 21-1 a Marker for Treatment Failure in Patients With Oropharyngeal Cancer Treated by Radio(chemo)therapy.

BACKGROUND: Primary radio(chemo)therapy [R(C)T] is a treatment option for advanced oropharyngeal squamous cell carcinoma (OSCC). Nevertheless, early diagnostics of treatment failure is problematic. Cytokeratin fragment 19 (CYFRA 21-1), an established marker in the management of pulmonary cancer, might be helpful here. Hence, in this study the impact of CYFRA 21-1 as an indicator for treatment failure and tumor recurrence (TR) in OSCC after R(C)T was analyzed. PATIENTS AND METHODS: The data of 77 patients with advanced OSCC and R(C)T were retrospectively examined. For determination of CYFRA 21-1 at the time of diagnosis and after R(C)T, an electrochemiluminescence immunoassay was used. Tumor residuals and tumor recurrence were pathologically verified after detection by radiological imaging and endoscopy. The mean follow-up was 44.4 months. RESULTS: After R(C)T, 48 (62%) patients showed locoregional control and 29 (38%) patients experienced locoregional failure. No statistical difference in the CYFRA 21-1 level between groups both before (p=0.75) and after R(C)T (p=0.85) was found. Nevertheless, in cases of TR in follow-up, the CYFRA 21-1 level was significantly higher (p≤0.01). The occurrence of TR was significantly associated with a CYFRA 21-1 elevation at this time (p≤0.01). However, CYFRA 21-1 failed to show a suitable discriminative ability for TR (area under the curve=0.57). CONCLUSION: In OSCC, CYFRA 21-1 does not seem to be a useful marker for locoregional failure after R(C)T. Nevertheless, a higher level immediately after R(C)T and in the further course of the disease may be associated with TR in individual patients.

Senescence markers in focal nodular hyperplasia of the liver: pathogenic considerations on the basis of immunohistochemical results.

Focal nodular hyperplasia (FNH) is a polyclonal tumour-like hepatic lesion characterised by parenchymal nodules, connective tissue septa without interlobular bile ducts, pronounced ductular reaction and inflammation. It may represent a response to local arterial hyperperfusion and hyperoxygenation resulting in oxidative stress. We aimed at obtaining closer insight into the pathogenesis of FNH with its characteristic morphologic features. Immunohistochemistry and immunofluorescence microscopy was performed on FNH specimens using antibodies against keratins (K) 7 and 19, neural cell adhesion molecule (NCAM), lamin B1, senescence markers (CDK inhibitor 1/p21Cip1, CDK inhibitor /p16Ink4a, senescence-associated (SA) ß- galactosidase activity), proliferation markers (Ki-67, proliferating-cell nuclear antigen (PCNA)), and the abnormally phosphorylated histone γ-H2AX, indicating DNA double strand breaks; moreover SA ß- galactosidase activity was determined histochemically. Ductular metaplasia of hepatocytes indicated by K7 expression in the absence of K19 plays a major role in the development of ductular reaction in FNH. Moreover, the expression of senescence markers (p21Cip1, p16Ink4a, γ-H2AX, SA ß-galactosidase activity) in hepatocytes and cholangiocytes suggests that stress-induced cellular senescence contributes to fibrosis and inflammation via production of components of the senescence-associated secretory phenotype. Expression of proliferation markers (Ki-67, PCNA) was not enhanced in hepatocytes and biliary cells. Senescence and ductular metaplasia of hepatocytes may thus be involved in inflammation, fibrosis and apoptosis resistance. Hence, fibrosis, inflammation and reduced apoptotic cell death, rather than proliferation (hyperplasia) may be responsible for increased tissue mass and tumour-like appearance of FNH.

Downregulation of MMP-9 Enhances the Anti-Migratory Effect of Cyclophosphamide in MDA-MB-231 and MCF-7 Breast Cancer Cell Lines.

Metastasis is one of the most urgent issues in breast cancer patients. One of the factors necessary in the migration process is the remodeling of the extracellular matrix (ECM). Metalloproteinases (MMPs) can break down the elements of the ECM, which facilitates cell movement. Many highly aggressive tumors are characterized by high levels of MMPs. In the case of breast cancer, the association between MMP-9 and the migration potential and invasiveness of cells has been demonstrated. In addition, reports indicating increased migration of breast cancer cells after the administration of the commonly used cytostatic cyclophosphamide (CP) are particularly disturbing. Hence, our research aimed to assess the effect of CP treatment on MDA-MB-231 and MCF-7 cells and how this response is influenced by the downregulation of the MMP-9 level. The obtained results suggest that CP causes a decrease in the survival of breast cancer cells of various invasiveness, and the downregulation of MMP-9 enhances this effect, mainly by inducing apoptosis. Moreover, in the group of MMP-9 siRNA-transfected CP-treated cells, a more severe reduction in invasion and migration of cells of both lines was observed, as indicated by the migration and invasion transwell assays and Wound healing assay. Hence, we suggest that CP alone may not result in satisfactory therapeutic effects. On the other hand, the use of combination therapy targeting MMP-9, together with the CP, could improve the effectiveness of the treatment. Additionally, we confirmed a relationship between the levels of MMP-9 and cytokeratin 19 (CK19).