The WAVE3/β-catenin oncogenic signaling regulates chemoresistance in triple negative breast cancer

CRISPR/Cas9 system: a novel approach to overcome chemotherapy and radiotherapy resistance in cancer

Cancer presents a global health challenge with rising incidence and mortality. Despite treatment advances in cancer therapy, radiotherapy and chemotherapy remained the most common treatments for all types of cancers. However, resistance phenotype in cancer cells leads to unsatisfactory results in the efficiency of therapeutic strategies. Therefore, researchers strive to propose effective solutions to overcome treatment failure, which requires a deep knowledge of treatment-resistant mechanisms. The progression and occurrence of tumors can be attributed to gene mutation. Over the past decade, the emergence of clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR/Cas9) genome editing has revolutionized cancer research. This versatile technology enables cancer modeling, manipulation of specific DNA sequences, and genome-wide screening. CRISPR/Cas9 is an effective tool for identifying radio- and chemoresistance genes and offering potential adjunctive treatments to overcome tumor recurrence after chemo- and radiotherapy. This article aims to explain the potential of the CRISPR/Cas9 system in improving the effectiveness of chemo- and radiotherapy and ultimately overcoming treatment failure.

The WASP/WAVE Protein Family in Breast Cancer and Their Role in the Metastatic Cascade

The Wiskott-Aldrich syndrome protein (WASP) and the WASP family verprolin-homologous protein (WAVE) family are essential molecules that connect GTPases to the actin cytoskeleton, thereby controlling actin polymerisation through the actin-related protein 2/3 complex. This control is crucial for forming actin-based membrane protrusions necessary for cell migration and invasion. The elevated expression of WASP/WAVE proteins in invasive breast cancer cells highlights their significant role in promoting cell motility and invasion. This review summarises the discovery, structural properties, and activation mechanisms of WASP/WAVE proteins, focuses on the contribution of the WASP/WAVE family to breast cancer invasion and migration, particularly synthesises the results of nearly a decade of research in this field since 2015. By exploring promising therapeutic strategies for breast cancer, including small molecule inhibitors and biological agents, this review stresses the potential for developing anticancer drugs that target the WASP/WAVE family and associated pathways, intending to improve the prognosis for patients with metastatic breast cancer.

Role of WAVE3 as an actin binding protein in the pathology of triple negative breast cancer

Breast cancer, a prevalent global health concern, has sparked extensive research efforts, particularly focusing on triple negative breast cancer (TNBC), a subtype lacking estrogen receptor (ER), progesterone receptor, and epidermal growth factor receptor. TNBC's aggressive nature and resistance to hormone-based therapies heightens the risk of tumor progression and recurrence. Actin-binding proteins, specifically WAVE3 from the Wiskott-Aldrich syndrome protein (WASP) family, have emerged as major drivers in understanding TNBC biology. This review delves into the intricate molecular makeup of TNBC, shedding light on actin's fundamental role in cellular processes. Actin, a structural element in the cytoskeleton, regulates various cellular pathways essential for homeostasis. Its dynamic nature enables functions such as cell migration, motility, intracellular transport, cell division, and signal transduction. Actin-binding proteins, including WAVE3, play pivotal roles in these processes. WAVE3, a member of the WASP family, remains the focus of this review due to its potential involvement in TNBC progression. While actin-binding proteins are studied for their roles in healthy cellular cycles, their significance in TNBC remains underexplored. This review aims to discuss WAVE3's impact on TNBC, exploring its molecular makeup, functions, and significance in tumor progression. The intricate structure of WAVE3, featuring elements like the verprolin-cofilin-acidic domain and regulatory elements, plays a crucial role in regulating actin dynamics. Dysregulation of WAVE3 in TNBC has been linked to enhanced cell migration, invasion, extracellular matrix remodeling, epithelial-mesenchymal transition, tumor proliferation, and therapeutic resistance. Understanding the role of actin-binding proteins in cancer biology has potential clinical implications, making them potential prognostic biomarkers and promising therapeutic targets. The review emphasizes the need for further research into actin-binding proteins' clinical applications, diagnostic value, and therapeutic interventions. In conclusion, this comprehensive review explores the complex interplay between actin and actin-binding proteins, with special emphasis on WAVE3, in the context of TNBC. By unraveling the molecular intricacies, structural characteristics, and functional significance, the review paves the way for future research directions, clinical applications, and potential therapeutic strategies in the challenging landscape of TNBC.

PSIP1 promotes gefitinib resistance in lung adenocarcinoma by inducing the expression of WASF3 and its downstream ITGB3/AKT signaling

BACKGROUND

Gefitinib (GR), a representative drug of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is a key pillar in the treatment of lung adenocarcinoma (LUAD), but drug resistance is universal. Identifying the potential factors of drug resistance to GR is essential to treat patients with EGFR mutant LUAD.

METHODS

The GR-resistant LUAD cells were established and confirmed by MTT assay. The effects of PC4 and SRSF1 interacting protein 1 (PSIP1) on GR-resistant cell proliferation and apoptosis in vitro and in vivo were detected by colony formation, flow cytometry, tumor-bearing animal model, immunohistochemistry, and TUNEL staining. Western blotting and qPCR were used to determine the expression of relevant markers. The effect of PSIP1 on the promoter region of Wiskott-Aldrich syndrome protein family member 3 (WASF3) was detected by the dual-luciferase assay. The interaction between PSIP1 and RNA polymerase II was evaluated using ChIP-qPCR and Co-IP assays.

RESULTS

PSIP1 was highly enriched in GR-resistant LUAD cells. Downregulation of PSIP1 expression significantly inhibited the proliferation of LUAD-resistant cells and promoted apoptosis. WASF3 was shown to have similar effects as PSIP1 in promoting drug resistance in LUAD cells. PSIP1 promoted the transcriptional activity of WASF3, which was achieved by increasing RNA polymerase II recruitment on the WASF3 promoter. Furthermore, PSIP1 positively regulated the expression of the pro-EGFR-TKI resistance factor integrin subunit beta 3 (ITGB3).

CONCLUSION

Our work suggests that PSIP1 promotes resistance to GR in LUAD cells by inducing the expression of WASF3 and its downstream regulator ITGB3.

HSP27/IL-6 axis promotes OSCC chemoresistance, invasion and migration by orchestrating macrophages via a positive feedback loop

Novel strategies to disrupt tumor progression have emerged from studying the interactions between tumor cells and tumor-associated macrophages (TAMs). However, the molecular mechanisms of interactions between tumor cells and TAMs underlying oral squamous cell carcinoma (OSCC) progression have not been fully elucidated. This study explored the molecular mechanism of the HSP27/IL-6 axis in OSCC chemoresistance, invasion, and migration. Here, we demonstrated the higher expression of HSP27 in OSCC cells. Paracrine HSP27 from OSCC cells enhanced chemoresistance, invasion, migration, and EMT in OSCC by inducing M2 polarization and IL-6 secretion in TAMs. HSP27 and IL-6 established a positive feedback loop between OSCC cells and M2 TAMs. TAMs-derived IL-6 orchestrated OSCC stemness and chemoresistance through upregulating β-catenin and CD44, and enhanced OSCC invasion, migration, and EMT via autocrine HSP27/TLR4 signaling. Collectively, HSP27/IL-6 axis facilitates OSCC chemoresistance, invasion, and migration by orchestrating macrophages through a positive feedback loop. We identify the regulatory mechanism underlying the interaction and crosstalk between OSCC cells and TAMs mediated by the HSP27/IL-6 axis. Targeting the HSP27/IL-6 axis could be a promising treatment strategy for OSCC patients, potentially controlling disease progression and improving prognosis and recurrence outcomes.

Kindlin-2 regulates the oncogenic activities of integrins and TGF-β in triple-negative breast cancer progression and metastasis

Kindlin-2, an adapter protein, is dysregulated in various human cancers, including triple-negative breast cancer (TNBC), where it drives tumor progression and metastasis by influencing several cancer hallmarks. One well-established role of Kindlin-2 involves the regulation of integrin signaling, achieved by directly binding to the cytoplasmic tail of the integrin β subunit. In this study, we present novel insights into Kindlin-2's involvement in stabilizing the β1-Integrin:TGF-β type 1 receptor (TβRI) complexes, acting as a physical bridge that links β1-Integrin to TβRI. Loss of Kindlin-2 results in the degradation of this protein complex, leading to the inhibition of downstream oncogenic pathways. We used a diverse range of in vitro assays, including CRISPR/Cas9 gene editing, cell migration, 3D-tumorsphere formation and invasion, solid binding, co-immunoprecipitation, cell adhesion and spreading assays, as well as western blot and flow cytometry analyses, utilizing MDA-MB-231 and 4T1 TNBC cell lines. Additionally, preclinical in vivo mouse models of TNBC tumor progression and metastasis were employed to substantiate our findings. Our studies established the direct interaction between Kindlin-2 and β1-Integrin and between Kindlin-2 and TβRI. Disruption of these interactions, via CRISPR/Cas9-mediated knockout of Kindlin-2, led to the degradation of β1-Integrin and TβRI, resulting in the inhibition of oncogenic pathways downstream of both proteins, subsequently hindering tumor growth and metastasis. Treatment of Kindlin-2-deficient cells with the proteasome inhibitor MG-132 restored the expression of both β1-Integrin and TβRI. Furthermore, the rescue of Kindlin-2 expression reinstated their oncogenic activities in vitro and in vivo, while Kindlin-2 lacking domains involved in the interaction of Kindlin-2 with β1-Integrin or TβRI did not. This study identifies a novel function of Kindlin-2 in stabilizing the β1-Integrin:TβRI complexes and regulating their downstream oncogenic signaling. The translational implications of these findings are substantial, potentially unveiling new therapeutically targeted pathways crucial for the treatment of TNBC tumors.

Kindlin-2 Regulates the Oncogenic Activities of Integrins and TGF-β In Triple Negative Breast Cancer Progression and Metastasis

Background

Kindlin-2, an adaptor protein, is dysregulated in various human cancers, including triple negative breast cancer (TNBC), where it drives tumor progression and metastasis by influencing several cancer hallmarks. One well-established role of Kindlin-2 involves the regulation of integrin signaling, achieved by directly binding to the cytoplasmic tail of the integrin β subunit. In this study, we present novel insights into Kindlin-2's involvement in stabilizing the β1-Integrin:TGF-β type 1 receptor (TβRI) complexes, acting as a physical bridge that links β1-Integrin to TβRI. The loss of Kindlin-2 results in the degradation of this protein complex, leading to the inhibition of downstream oncogenic pathways.

Methods

Our methodology encompassed a diverse range of in vitro assays, including CRISPR/Cas9 gene editing, cell migration, 3D tumorsphere formation and invasion, solid binding, co-immunoprecipitation, cell adhesion and spreading assays, as well as western blot and flow cytometry analyses, utilizing MDA-MB-231 and 4T1 TNBC cell lines. Additionally, preclinical in vivo mouse models of TNBC tumor progression and metastasis were employed to substantiate our findings.

Results

The investigation revealed that the direct interaction between Kindlin-2 and β1-Integrin is mediated through the C-terminal F3 domain of Kindlin-2, while the interaction between Kindlin-2 and TβRI is facilitated through the F2 domain of Kindlin-2. Disruption of this bridge, achieved via CRISPR/Cas9-mediated knockout of Kindlin-2, led to the degradation of β1-Integrin and TβRI, resulting in the inhibition of oncogenic pathways downstream of both proteins, subsequently hindering tumor growth and metastasis. Treatment of Kindlin-2-deficient cells with the proteasome inhibitor MG-132 restored the expression of both β1-Integrin and TβRI. Furthermore, the rescue of Kindlin-2 expression reinstated their oncogenic activities both in vitro and in vivo.

Conclusions

This study identifies a novel function of Kindlin-2 in stabilizing the β1-Integrin:TβR1 complexes and regulating their downstream oncogenic signaling. The translational implications of these findings are substantial, potentially unveiling new therapeutically targeted pathways crucial for the treatment of TNBC tumors.

Identification and characterization of ARID1A-interacting proteins in renal tubular cells and their molecular regulation of angiogenesis

BACKGROUND

Defects and deficiency of AT-rich interactive domain-containing protein 1A (ARID1A) encoded by a tumor suppressor gene ARID1A have recently been suggested to get involved in angiogenesis, a crucial process in carcinogenesis. However, molecular mechanisms of ARID1A deficiency to induce angiogenesis in kidney cancer remain underinvestigated.

METHODS

We performed large-scale identification of ARID1A protein interactors in renal tubular epithelial cells (RTECs) using immunoprecipitation (IP) followed by nanoLC-ESI-LTQ-Orbitrap tandem mass spectrometry (MS/MS). Their roles in angiogenesis were investigated using various assays.

RESULTS

A total of 74 ARID1A-interacting proteins were identified. Protein-protein interactions analysis revealed that these identified proteins interacted directly or indirectly with ARID1A. Among them, the direct interaction between ARID1A and β-actin was validated by IP and reciprocal IP followed by Western blotting. Small interfering RNA (siRNA) was used for single and double knockdowns of ARID1A and ACTB. Semi-quantitative RT-PCR demonstrated that deficiency of ARID1A, but not ACTB, significantly affected expression of angiogenesis-related genes in RTECs (VEGF and FGF2 were increased, whereas PDGF and EGF were decreased). However, the knockdowns did not affect TGFB1 and FGF1 levels. The quantitative mRNA expression data of VEGF and TGFB1 were consistent with the secreted levels of their protein products as measured by ELISA. Only secreted products derived from ARID1A-deficient RTECs significantly increased endothelial cells (ECs) migration and tube formation. Some of the other carcinogenic features could also be confirmed in the ARID1A-deficient RTECs, including increased cell migration and chemoresistance. Double knockdowns of both ARID1A and ACTB did not enhance the effects of single ARID1A knockdown in all assays.

CONCLUSIONS

We report herein a large dataset of the ARID1A-interacting proteins in RTECs using an IP-MS/MS approach and confirm the direct interaction between ARID1A and β-actin. However, the role of ARID1A deficiency in angiogenesis is independent of β-actin.