Local Wnt signalling in the asymmetric migrating vertebrate cells

Proanthocyanidins inhibited colorectal cancer stem cell characteristics through Wnt/β-catenin signaling

BACKGROUND

Cancer stem cells (CSCs) play a key role in tumor cell growth, drug resistance, recurrence, and metastasis. Proanthocyanidins (PC) is widely existed in plants and endowed with powerful antioxidant and anti-aging effects. Interestingly, recent studies have found that PC exhibits the inhibitory effect on tumor growth. However, the role of PC in CSCs of colorectal cancer (CRC) and molecular mechanism remain unclear.

METHODS

CCK-8, colony, and tumorsphere formation assay were used to evaluate cancer cell viability and stemness, respectively. Western blotting was used to detect the protein expression. Tumor xenograft experiments were employed to examine the tumorigenicity of CRC cells in nude mice.

RESULTS

PC decreased the proliferation of CRC cells (HT29 and HCT-116), and improved the sensitivity of CRC cells to oxaliplatin (L-OHP), as well as inhibited tumor growth in nude mice. Further studies showed that PC also down-regulated CSCs surface molecular and stemness transcriptional factors, while suppressed the formations of tumorspheres and cell colony in CRC. In addition, PC-impaired proteins expressions of p-GSK3β, β-catenin and DVL1-3. LiCl, an activator of the Wnt/β-catenin signaling, rescued PC-induced downregulation of CSCs markers, and reduction of tumorspheres and cell colony formation abilities in CRC cells. Furthermore, the effects of PC on inhibiting cell proliferation and enhancing L-OHP sensitivity were impaired by LiCl.

CONCLUSIONS

PC exerted an inhibitory effect on CSCs via Wnt/β-catenin in CRC, and may be a potential new class of natural drug for CRC treatment.

Molecular Alterations and Putative Therapeutic Targeting of Planar Cell Polarity Proteins in Breast Cancer

BACKGROUND

Treatment and outcomes of breast cancer, one of the most prevalent female cancers, have improved in recent decades. However, metastatic breast cancer remains incurable in most cases, and new therapies are needed to ameliorate prognosis. Planar cell polarity (PCP) is a characteristic of epithelial cells that form layers and is integral to the communication of these cells with neighboring cells. Dysfunction of PCP is observed in cancers and may confer a targetable vulnerability.

METHODS

The breast cancer cohorts from The Cancer Genome Atlas (TCGA) and the METABRIC study were interrogated for molecular alterations in genes of the PCP pathway. The groups with the most prevalent alterations were characterized, and survival was compared with counterparts not possessing PCP alterations. Breast cancer cell lines with PCP alterations from the Cancer Cell Line Encyclopedia (CCLE) were interrogated for sensitivity to drugs affecting PCP.

RESULTS

Among genes of the PCP pathway, VANGL2, NOS1AP and SCRIB display amplifications in a sizable minority of breast cancers. Concomitant up-regulation at the mRNA level can be observed mostly in basal cancers, but it does not correlate well with the amplification status of the genes, as it can also be observed in non-amplified cases. In an exploration of cell line models, two of the four breast cancer cell line models with amplifications in VANGL2, NOS1AP and SCRIB display sensitivity to drugs inhibiting acyl-transferase porcupine interfering with the WNT pathway. This sensitivity suggests a possible therapeutic role of these inhibitors in cancers bearing the amplifications.

CONCLUSION

Molecular alterations in PCP genes can be observed in breast cancers with a predilection for the basal sub-type. An imperfect correlation of copy number alterations with mRNA expression suggests that post-translational modifications are important in PCP regulation. Inhibitors of acyl-transferase porcupine may be rational candidates for combination therapy development in PCP-altered breast cancers.

Cannabigerol Activates Cytoskeletal Remodeling via Wnt/PCP in NSC-34: An In Vitro Transcriptional Study

Cannabigerol (CBG) is a non-psychoactive phytocannabinoid present in the Cannabis sativa L. plant. In our study, CBG at the concentration of 10 µM was used to treat NSC-34 motor neuron-like cells. The aim of the study was to evaluate the effects of CBG on NSC-34 cells, using next-generation sequencing (NGS) technology. Analysis showed the activation of the WNT/planar cell polarity (PCP) pathway and Ephrin-Eph signaling. The results revealed that CBG increases the expression of genes associated with the onset process of cytoskeletal remodeling and axon guidance.

Role of casein kinase 1 in the amoeboid migration of B-cell leukemic and lymphoma cells: A quantitative live imaging in the confined environment

The migratory properties of leukemic cells are commonly associated with their pathological potential and can significantly affect the disease progression. While the research in immunopathology mostly employed powerful indirect methods such as flow cytometry, these cells were rarely observed directly using live imaging microscopy. This is especially true for the malignant cells of the B-cell lineage, such as those originating from chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). In this study, we employed open-source image analysis tools to automatically and quantitatively describe the amoeboid migration of four B-cell leukemic and lymphoma cell lines and primary CLL cells. To avoid the effect of the shear stress of the medium on these usually non-adherent cells, we have confined the cells using a modified under-agarose assay. Surprisingly, the behavior of tested cell lines differed substantially in terms of basal motility or response to chemokines and VCAM1 stimulation. Since casein kinase 1 (CK1) was reported as a regulator of B-cell migration and a promoter of CLL, we looked at the effects of CK1 inhibition in more detail. Migration analysis revealed that CK1 inhibition induced rapid negative effects on the migratory polarity of these cells, which was quantitatively and morphologically distinct from the effect of ROCK inhibition. We have set up an assay that visualizes endocytic vesicles in the uropod and facilitates morphological analysis. This assay hints that the effect of CK1 inhibition might be connected to defects in polarized intracellular transport. In summary, 1) we introduce and validate a pipeline for the imaging and quantitative assessment of the amoeboid migration of CLL/MCL cells, 2) we provide evidence that the assay is sensitive enough to mechanistically study migration defects identified by the transwell assay, and 3) we describe the polarity defects induced by inhibition or deletion of CK1ε.

Nuclear Dishevelled: An enigmatic role in governing cell fate and Wnt signaling

The Dishevelled gene was first identified in Drosophila mutants with disoriented hair and bristle polarity and subsequent work has now demonstrated its importance in critical and diverse aspects of biology. Since those early discoveries, Dishevelled has been shown to coordinate a plethora of developmental and cellular processes that range from controlling cell polarity during gastrulation to partnering with chromatin modifying enzymes to regulate histone methylation at genomic loci. While the role of DVL in development is well-respected and the cytosolic function of DVL has been studied more extensively, its nuclear role continues to remain murky. In this review we highlight some of the seminal discoveries that have contributed to the field, but the primary focus is to discuss recent advances with respect to the nuclear role of Dishevelled. This nuclear function of Dishevelled is a dimension which is proving to be increasingly important yet remains enigmatic.