Expression of kinesin family member C1 in pancreatic ductal adenocarcinoma affects tumor progression and stemness

Discovering cancer stem-like molecule, nuclear factor I X, using spatial transcriptome in gastric cancer

Gastric cancer (GC) is characterized by significant intratumoral heterogeneity, and stem cells are promising therapeutic targets. Despite advancements in spatial transcriptome analyses, unexplored targets for addressing cancer stemness remain unknown. This study aimed to identify Nuclear Factor IX (NFIX) as a critical regulator of cancer stemness in GC and evaluate its clinicopathological significance and function. Spatial transcriptome analysis of GC was conducted. The correlation between NFIX expression, clinicopathological factors, and prognosis was assessed using immunostaining in 127 GC cases. Functional analyses of cancer cell lines validated these findings. Spatial transcriptome analysis stratified GC tissues based on genetic profiles, identified CSC-like cells, and further refined the classification to identify and highlight the significance of NFIX, as validated by Monocle 3 and CytoTRACE analyses. Knockdown experiments in cancer cell lines have demonstrated the involvement of NFIX in cancer cell proliferation and kinase activity. This study underscores the role of spatial transcriptome analysis in refining GC tissue classification and identifying therapeutic targets, highlighting NFIX as a pivotal factor. NFIX expression is correlated with poor prognosis and drives GC progression, suggesting its potential as a novel therapeutic target for personalized GC therapies.

The DDX6/KIFC1 signaling axis, as regulated by YY1, contributes to the malignant behavior of pancreatic cancer

Human DEAD/H box RNA helicase DDX6 acts as an oncogene in several different types of cancer, where it participates in RNA processing. Nevertheless, the role of DDX6 in pancreatic cancer (PC), together with the underlying mechanism, has yet to be fully elucidated. In the present study, compared with adjacent tissues, the level of DDX6 was abnormally increased in human PC tissues, and this increased level of expression was associated with poor prognosis. Furthermore, the role of DDX6 in PC was investigated by overexpressing or silencing the DDX6 in the PC cell lines, SW1990 and PaTu-8988t. A xenograft model was established by injecting nude mice with either DDX6-overexpressing or DDX6-silenced SW1990 cells. DDX6 overexpression promoted the proliferation and cell cycle transition, inhibited the cell apoptosis of PC cells, and accelerated tumor formation, whereas DDX6 knockdown elicited the opposite effects. DDX6 exerted positive effects on PC. RNA immunoprecipitation assay showed that DDX6 bound to kinesin family member C1 (KIFC1) mRNA, which was further confirmed by RNA pull-down assay. These results suggested that DDX6 positively regulated the expression of KIFC1. KIFC1 overexpression enhanced the proliferative capability of PC cells with DDX6 knockdown and inhibited their apoptosis. By contrast, DDX6 overexpression reversed the inhibitory effect of KIFC1 silencing on tumor proliferation. Subsequently, the transcription factor Yin Yang 1 (YY1) was shown to negatively regulate DDX6 at both the mRNA and protein levels. Dual-luciferase reporter assay verified that YY1 targeted the promoter of DDX6 and inhibited its transcription. High expression levels of YY1 decreased the proliferation of PC cells and promoted cell apoptosis, although these effects were reversed by DDX6 overexpression. Taken together, YY1 may target the DDX6/KIFC1 axis, thereby negatively regulating its expression, leading to an inhibitory effect on pancreatic tumor.

A comprehensive analysis of the prognostic and immunotherapeutic characteristics of KIFC1 in pan-cancer and its role in the malignant phenotype of pancreatic cancer

BACKGROUND

Kinesin family member C1 (KIFC1) is an essential member of the motor protein family, which is critically involved in various cellular events, such as mitosis, meiosis, and macromolecular transport, but also in carcinogenesis, malignant progression, and tumor recurrence.

METHODS

The analysis determined the relationship between KIFC1 expression, prognosis significance, immune characteristics landscape, and genetic alterations in pan-cancer with the data extracted from web-based platforms and databases, including but not limited to UCSC, NCBI, GEPIA2, HPA, cBioPortal, SangerBox, UALCAN, GEO and TCGA. Additionally, the expression of KIFC1 in pancreatic cancer tumor tissues and adjacent normal tissues was evaluated through immunohistochemistry. In vitro Edu, colony formation, wound healing, and Transwell assay were done to elucidate the biological functions of KIFC1 in pancreatic cancer cells.

RESULTS

The analysis revealed that KIFC1 is upregulated in most cancers, and its increased expression is significantly associated with reduced overall survival and disease-free survival in multiple cancer types. Additionally, strong correlations between KIFC1 expression and tumor immunotherapy were observed across various malignancies. Through univariate and multivariate Cox regression analyses using TCGA data, KIFC1 was identified as an independent predictor of prognosis in pancreatic cancer cases. Furthermore, cellular experiments demonstrated that knockdown of KIFC1 resulted in the suppression of cell proliferation, migration, and invasive ability.

CONCLUSIONS

Our study indicated that KIFC1 harbors the potential to be a prognostic and immunotherapeutic biomarker of tumors, and it can have an impact on the metastasis and the cell cycle of pancreatic cancer cells.

IQ Motif Containing GTPase-Activating Protein 3 Is Associated with Cancer Stemness and Survival in Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of malignancy, with poor prognosis and rising incidence. IQ motif containing GTPase-activating protein 3 (IQGAP3) is a member of the IQGAPs family of scaffolding proteins that govern multiple cellular activities like cytoskeletal remodeling and cellular signal transduction. This study aimed to analyze the expression and biological function of IQGAP3 in PDAC.

METHODS

We analyzed IQGAP3 expression in 81 PDAC samples by immunohistochemistry. RNA interference was used to inhibit IQGAP3 expression in PDAC cell lines.

RESULTS

Immunohistochemical analysis of IQGAP3 showed that 54.3% of PDACs were positive for cytoplasmic expression of IQGAP3, with no expression found in non-neoplastic tissue. Furthermore, IQGAP3 expression was an independent poor prognostic factor in our immunostaining-based studies and analyses of public databases. Our cohort and the Cancer Genome Atlas database indicated that IQGAP3 is co-localized with kinesin family member C1 (KIFC1), which we previously reported as a cancer stem cell-associated protein. IQGAP3 small interfering RNA treatment decreased PDAC cell proliferation and spheroid colony formation via ERK and AKT pathways.

DISCUSSION/CONCLUSION

These results suggest that IQGAP3, a transmembrane protein, is involved in survival and stemness and may be a promising new therapeutic target for PDAC.

Kinesin Family Member B18 Is Related to Gastric Mucin Phenotype and Contributes to Gastric Cancer Progression by Regulating Epithelial-Mesenchymal Transition

INTRODUCTION

Gastric cancer (GC) remains a common health concern worldwide and is the third leading cause of death in Japan. It can be broadly classified into gastric and intestinal mucin phenotypes using immunohistochemistry. We previously reported numerous associations of kinesin family member (KIF) genes and mucin phenotypes with GC. However, no previous studies have reported on the importance of KIF18B in GC using immunostaining. Thus, in this study, we investigated the expression and functions of KIF18B, which is highly expressed in gastric mucin phenotype GC.

METHODS

We performed RNA-seq of gastric and intestinal mucin type GCs, and clinicopathological studies of the KIF18B we found were performed using 96 GC cases. We also performed functional analysis using GC-derived cell lines.

RESULT

RNA-seq showed the upregulation of matrisome-associated genes in gastric mucin phenotype GC and a high expression of KIF18B. KIF18B was detected in 52 of the 96 GC cases (54%) through immunohistochemistry. Low KIF18B expression was significantly associated with poor overall survival (p < 0.01). Other molecules that were significantly associated with KIF18B were MUC5AC and claudin 18; these were also significantly associated with the gastric mucin phenotype. KIF18B small interfering RNA (siRNA)-transfected GC cells showed greater growth and spheroid colony formation than the negative control siRNA-transfected cells. Furthermore, expression of snail family transcriptional repressor 1 and cadherin 2 was significantly increased and that of cadherin 1 was significantly decreased in KIF18B siRNA-transfected GC cells.

CONCLUSION

These findings not only suggest that KIF18B may be a useful prognostic marker, but also provide insight into the pathogenesis of the GC phenotype.