The role of katanin p60 in breast cancer bone metastasis

Discovery of Novel Diaryl-Substituted Fused Heterocycles Targeting Katanin and Tubulin with Potent Antitumor and Antimultidrug Resistance Efficacy

Disrupting microtubule dynamics has emerged as a promising strategy for cancer treatment. However, drug resistance remains a challenge hindering the development of microtubule-targeting agents. In this work, a novel class of diaryl substituted fused heterocycles were designed, synthesized, and evaluated, which were demonstrated as effective dual katanin and tubulin regulators with antitumor activity. Following three rounds of stepwise optimization, compound 21b, featuring a 3H-imidazo[4,5-b]pyridine core, displayed excellent targeting capabilities on katanin and tubulin, along with notable antiproliferative and antimetastatic effects. Mechanistic studies revealed that 21b disrupts the microtubule network in tumor cells, leading to G2/M cell cycle arrest and apoptosis induction. Importantly, 21b exhibited significant inhibition of tumor growth in MDA-MB-231 and A549/T xenograft tumor models without evident toxicity and side effects. In conclusion, compound 21b presents a novel mechanism for disrupting microtubule dynamics, warranting further investigation as a dual-targeted antitumor agent with potential antimultidrug resistance properties.

A potential posttranscriptional regulator for p60-katanin: miR-124-3p

Katanin is a microtubule severing protein belonging to the ATPase family and consists of two subunits; p60-katanin synthesized by the KATNA1 gene and p80-katanin synthesized by the KATNB1 gene. Microtubule severing is one of the mechanisms that allow the reorganization of microtubules depending on cellular needs. While this reorganization of microtubules is associated with mitosis in dividing cells, it primarily takes part in the formation of structures such as axons and dendrites in nondividing mature neurons. Therefore, it is extremely important in neuronal branching. p60 and p80 katanin subunits coexist in the cell. While p60-katanin is responsible for cutting microtubules with its ATPase function, p80-katanin is responsible for the regulation of p60-katanin and its localization in the centrosome. Although katanin has vital functions in the cell, there are no known posttranscriptional regulators of it. MicroRNAs (miRNAs) are a group of small noncoding ribonucleotides that have been found to have important roles in regulating gene expression posttranscriptionally. Despite being important in gene regulation, so far no microRNA has been experimentally associated with katanin regulation. In this study, the effects of miR-124-3p, which we detected as a result of bioinformatics analysis to have the potential to bind to the p60 katanin mRNA, were investigated. For this aim, in this study, SH-SY5Y neuroblastoma cells were transfected with pre-miR-124-3p mimics and pre-mir miRNA precursor as a negative control, and the effect of this transfection on p60-katanin expression was measured at both RNA and protein levels by quantitative real-time PCR (qRT-PCR) and western blotting, respectively. The results of this study showed for the first time that miR-124-3p, which was predicted to bind p60-katanin mRNA by bioinformatic analysis, may regulate the expression of the KATNA1 gene. The data obtained within the scope of this study will make important contributions in order to better understand the regulation of the expression of p60-katanin which as well will have an incontrovertible impact on the understanding of the importance of cytoskeletal reorganization in both mitotic and postmitotic cells.

Emerging role of microtubule-associated proteins on cancer metastasis

The major cause of death in cancer patients is strongly associated with metastasis. While much remains to be understood, microtubule-associated proteins (MAPs) have shed light on metastatic progression’s molecular mechanisms. In this review article, we focus on the role of MAPs in cancer aggressiveness, particularly cancer metastasis activity. Increasing evidence has shown that a growing number of MAP member proteins might be fundamental regulators involved in altering microtubule dynamics, contributing to cancer migration, invasion, and epithelial-to-mesenchymal transition. MAP types have been established according to their microtubule-binding site and function in microtubule-dependent activities. We highlight that altered MAP expression was commonly found in many cancer types and related to cancer progression based on available evidence. Furthermore, we discuss and integrate the relevance of MAPs and related molecular signaling pathways in cancer metastasis. Our review provides a comprehensive understanding of MAP function on microtubules. It elucidates how MAPs regulate cancer progression, preferentially in metastasis, providing substantial scientific information on MAPs as potential therapeutic targets and prognostic markers for cancer management.

Susceptibility of cytoskeletal-associated proteins for tumor progression

The traditional functions of cytoskeletal-associated proteins (CAPs) in line with polymerization and stabilization of the cytoskeleton have evolved and are currently underrated in oncology. Although therapeutic drugs have been developed to target the cytoskeletal components directly in cancer treatment, several recently established therapeutic agents designed for new targets block the proliferation of cancer cells and suppress resistance to existing target agents. It would seem like these targets only work toward inhibiting the polymerization of cytoskeletal components or hindering mitotic spindle formation in cancer cells, but a large body of literature points to CAPs and their culpability in cell signaling, molecular conformation, organelle trafficking, cellular metabolism, and genomic modifications. Here, we review those underappreciated functions of CAPs, and we delineate the implications of cellular signaling instigated by evasive properties induced by aberrant expression of CAPs in response to stress or failure to exert normal functions. We present an analogy establishing CAPs as vulnerable targets for cancer systems and credible oncotargets. This review establishes a paradigm in which the cancer machinery may commandeer the conventional functions of CAPs for survival, drug resistance, and energy generation; an interesting feature overdue for attention.

The Mammalian Family of Katanin Microtubule-Severing Enzymes

The katanin family of microtubule-severing enzymes is critical for cytoskeletal rearrangements that affect key cellular processes like division, migration, signaling, and homeostasis. In humans, aberrant expression, or dysfunction of the katanins, is linked to developmental, proliferative, and neurodegenerative disorders. Here, we review current knowledge on the mammalian family of katanins, including an overview of evolutionary conservation, functional domain organization, and the mechanisms that regulate katanin activity. We assess the function of katanins in dividing and non-dividing cells and how their dysregulation promotes impaired ciliary signaling and defects in developmental programs (corticogenesis, gametogenesis, and neurodevelopment) and contributes to neurodegeneration and cancer. We conclude with perspectives on future katanin research that will advance our understanding of this exciting and dynamic class of disease-associated enzymes.

Katanin P60: a potential biomarker for lymph node metastasis and prognosis for non-small cell lung cancer

Background

This study aimed to assess the correlation of katanin P60 expression with clinical characteristics and survival profiles of surgical non-small cell lung cancer (NSCLC) patients.

Methods

Two hundred and sixty-five primary NSCLC patients treated by surgical resection were retrospectively viewed. The expression of katanin P60 in the tumor specimen was detected by the immunohistochemical (IHC) staining assay. Preoperative clinical data were collected from patients’ medical records, and survival data were extracted from follow-up records.

Results

There were 127 (47.9%) and 138 (52.1%) patients with katanin P60-low expression and -high expression, respectively; in addition, patients presenting katanin P60-high+, -high++, and -high+++ expression were 62 (23.4%), 63 (23.8%), and 13 (4.9%), respectively. Katanin P60 expression was correlated with lymph node (LYN) metastasis and advanced TNM stage but not pathological grade, tumor size, carcinoembryonic antigen (CEA) level or other non-tumor features in NSCLC patients. Regarding survival profiles, disease-free survival (DFS) and overall survival (OS) were both the lowest in katanin P60-high+++ expression patients, followed with katanin P60-high++ patients, katanin P60-high+ patients, and the highest in katanin P60-low expression patients. Further analysis illustrated that katanin P60-high expression was an independent predictive factor for unfavorable DFS and OS in NSCLC patients.

Conclusions

Katanin P60 presents potential as a biomarker for lymph node metastasis and prognosis in NSCLC patients.

Katanin P80 correlates with larger tumor size, lymph node metastasis, and advanced TNM stage and predicts poor prognosis in non-small-cell lung cancer patients

Objective

The present study aimed to investigate the correlation of katanin P80 expression with clinicopathological features and survival profile in non–small‐cell lung cancer (NSCLC) patients.

Methods

Totally, 398 NSCLC patients treated by pulmonary resection were enrolled and their tumor specimens were collected to determine katanin P80 expression by immunohistochemistry (IHC) assay. Clinical data were collected at diagnosis, and survival data including disease‐free survival (DFS) and overall survival (OS) were assessed after treatment.

Results

There were 195 (49.0%) patients with katanin P80 high expression and 203 (51.0%) patients with katanin P80 low expression, respectively. Meanwhile, katanin P80 high expression was associated with larger tumor size (P = .001), lymph node (LYN) metastasis (P = .005), and advanced TNM stage (P = .001). As for survival data, katanin P80 high expression was correlated with reduced DFS (P < .001) and OS (P < .001). And forward stepwise multivariate Cox's regression revealed that katanin P80 high expression was an independent predictor for decreased DFS (P < .001) and OS (P < .001). Besides, further analysis indicated that DFS (P < .001) and OS (P < .001) were the shortest in patients with katanin P80 high+++ expression, followed by patients with katanin P80 high++ expression and then those with katanin P80 high + expression and katanin P80 low expression.

Conclusion

Katanin P80 correlates with larger tumor size, LYN metastasis, and advanced TNM stage, and serves as a potential biomarker for predicting poor survival in NSCLC patients.

Clinical relevance of cytoskeleton associated proteins for ovarian cancer

PURPOSE

Ovarian cancer has a high mortality rate and up to now no reliable molecular prognostic biomarkers have been established. During malignant progression, the cytoskeleton is strongly altered. Hence we analyzed if expression of certain cytoskeleton-associated proteins is correlated with clinical outcome of ovarian cancer patients.

METHODS

First, in silico analysis was performed using the cancer genome atlas (TCGA), the human expression atlas and Pubmed. Selected candidates were validated on 270 ovarian cancer patients by qRT-PCR and/or by western blotting.

RESULTS

In silico analysis revealed that mRNAs of 214 cytoskeleton-associated proteins are detectable in ovarian cancer tissue. Among these, we selected 17 proteins that participate in cancer disease progression and cytoskeleton modulation: KIF14, KIF20A, KIF18A, ASPM, CEP55, DLGAP5, MAP9, EB1, KATNA1, DIAPH1, ANLN, SCIN, CCDC88A, FSCN1, GSN, VASP and CDC42. The first ten candidates interact with microtubules (MTs) and the others bind to actin filaments. Validation on clinical samples of ovarian cancer patients revealed that the expression levels of DIAPH1, EB1, KATNA1, KIF14 and KIF18A significantly correlated with clinical and histological parameters of ovarian cancer. High DIAPH1, EB1, KATNA1 and KIF14 protein levels were associated with increased overall survival (OAS) of ovarian cancer patients, while high DIAPH1 and EB1 protein levels were also associated with low differentiation of respective tumors (G2/3). Moreover, DIAPH1 was the only protein, whose expression significantly correlated with increased recurrence-free interval (RFI).

CONCLUSION

Mainly the expression levels of the MT-associated proteins analyzed in this study, correlated with prolonged survival of ovarian cancer patients. From > 200 genes initially considered, 17 cytoskeletal proteins are involved in cancer progression according to the literature. Among these, four proteins significantly correlated with improved survival of ovarian cancer patients.