MET inhibition enhances PARP inhibitor efficacy in castration-resistant prostate cancer by suppressing the ATM/ATR and PI3K/AKT pathways

Unlocking c-MET: A comprehensive journey into targeted therapies for breast cancer

Breast cancer is the most common malignancy among women, posing a formidable health challenge worldwide. In this complex landscape, the c-MET (cellular-mesenchymal epithelial transition factor) receptor tyrosine kinase (RTK), also recognized as the hepatocyte growth factor (HGF) receptor (HGFR), emerges as a prominent protagonist, displaying overexpression in nearly 50% of breast cancer cases. Activation of c-MET by its ligand, HGF, secreted by neighboring mesenchymal cells, contributes to a cascade of tumorigenic processes, including cell proliferation, metastasis, angiogenesis, and immunosuppression. While c-MET inhibitors such as crizotinib, capmatinib, tepotinib and cabozantinib have garnered FDA approval for non-small cell lung cancer (NSCLC), their potential within breast cancer therapy is still undetermined. This comprehensive review embarks on a journey through structural biology, multifaceted functions, and intricate signaling pathways orchestrated by c-MET across cancer types. Furthermore, we highlight the pivotal role of c-MET-targeted therapies in breast cancer, offering a clinical perspective on this promising avenue of intervention. In this pursuit, we strive to unravel the potential of c-MET as a beacon of hope in the fight against breast cancer, unveiling new horizons for therapeutic innovation.

Small molecule agents for triple negative breast cancer: Current status and future prospects

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with poor prognosis. The number of cases increased by 2.26 million in 2020, making it the most commonly diagnosed cancer type in the world. TNBCs lack hormone receptor (HR) and human epidermal growth factor 2 (HER2), which limits treatment options. Currently, paclitaxel-based drugs combined with other chemotherapeutics remain the main treatment for TNBC. There is currently no consensus on the best therapeutic regimen for TNBC. However, there have been successful clinical trials exploring large-molecule monoclonal antibodies, small-molecule targeted drugs, and novel antibody-drug conjugate (ADC). Although monoclonal antibodies have produced clinical success, their large molecular weight can limit therapeutic benefits. It is worth noting that in the past 30 years, the FDA has approved small molecule drugs for HER2-positive breast cancers. The lack of effective targets and the occurrence of drug resistance pose significant challenges in the treatment of TNBC. To improve the prognosis of TNBC, it is crucial to search for effective targets and to overcome drug resistance. This review examines the clinical efficacy, adverse effects, resistance mechanisms, and potential solutions of targeted small molecule drugs in both monotherapies and combination therapies. New therapeutic targets, including nuclear export protein 1 (XPO1) and hedgehog (Hh), are emerging as potential options for researchers and become integrated into clinical trials for TNBC. Additionally, there is growing interest in the potential of targeted protein degradation chimeras (PROTACs), degraders of rogue proteins, as a future therapy direction. This review provides potentially valuable insights with clinical implications.

Effect of ubiquitin protease system on DNA damage response in prostate cancer (Review)

Genomic instability is an essential hallmark of cancer, and cellular DNA damage response (DDR) defects drive tumorigenesis by disrupting genomic stability. Several studies have identified abnormalities in DDR-associated genes, and a dysfunctional ubiquitin-proteasome system (UPS) is the most common molecular event in metastatic castration-resistant prostate cancer (PCa). For example, mutations in Speckle-type BTB/POZ protein-Ser119 result in DDR downstream target activation deficiency. Skp2 excessive upregulation inhibits homologous recombination repair and promotes cell growth and migration. Abnormally high expression of a deubiquitination enzyme, ubiquitin-specific protease 12, stabilizes E3 ligase MDM2, which further leads to p53 degradation, causing DDR interruption and genomic instability. In the present review, the basic pathways of DDR, UPS dysfunction, and its induced DDR alterations mediated by genomic instability, and especially the potential application of UPS and DDR alterations as biomarkers and therapeutic targets in PCa treatment, were described.

NAD+-A Hub of Energy Metabolism in Heart Failure

Heart failure is a condition where reduced levels of adenosine triphosphate (ATP) affect energy supply in myocardial cells. Nicotinamide adenine dinucleotide (NAD+) plays a crucial role as a coenzyme for electron transfer in energy metabolism. Decreased NAD+ levels in myocardial cells lead to inadequate ATP production and increased susceptibility to heart failure. Researchers are exploring ways to increase NAD+ levels to alleviate heart failure. Targets such as sirtuin2 (sirt2), sirtuin3 (sirt3), Poly (ADP-ribose) polymerase (PARP), and diastolic regulatory proteins are being investigated. NAD+ supplementation has shown promise, even in heart failure with preserved ejection fraction (HFpEF). By focusing on NAD+ as a central component of energy metabolism, it is possible to improve myocardial activity, heart function, and address energy deficiency in heart failure.

PI3K/Akt signaling in urological cancers: Tumorigenesis function, therapeutic potential, and therapy response regulation

In addition to environmental conditions, lifestyle factors, and chemical exposure, aberrant gene expression and mutations involve in the beginning and development of urological tumors. Even in Western nations, urological malignancies are among the top causes of patient death, and their prevalence appears to be gender dependent. The prognosis for individuals with urological malignancies remains dismal and unfavorable due to the ineffectiveness of conventional treatment methods. PI3K/Akt is a popular biochemical mechanism that is activated in tumor cells as a result of PTEN loss. PI3K/Akt escalates growth and metastasis. Moreover, due to the increase in tumor cell viability caused by PI3K/Akt activation, cancer cells may acquire resistance to treatment. This review article examines the function of PI3K/Akt in major urological tumors including bladder, prostate, and renal tumors. In prostate, bladder, and kidney tumors, the level of PI3K and Akt are notably elevated. In addition, the activation of PI3K/Akt enhances the levels of Bcl-2 and XIAP, hence increasing the tumor cell survival rate. PI3K/Akt ] upregulates EMT pathways and matrix metalloproteinase expression to increase urological cancer metastasis. Furthermore, stimulation of PI3K/Akt results in drug- and radio-resistant cancers, but its suppression by anti-tumor drugs impedes the tumorigenesis.

Knockdown of KIF15 suppresses proliferation of prostate cancer cells and induces apoptosis through PI3K/Akt signaling pathway

Prostate cancer is one of the most common malignancies in men, which has been considered a public health threat. KIF15 is a kind of driver protein, and its abnormal expression is closely related to the occurrence and development of malignant tumors. The purpose of the study was to explore the significance and role of KIF15 in prostate cancer and to show some potential value for prostate cancer. Immunohistochemistry analysis showed that KIF15 was highly expressed in prostate cancer tissues, which was also positively correlated with T Infiltrate. The loss-of-function and gain-of-function assays based on prostate cancer cells indicated that the change in KIF15 expression could significantly affect cell proliferation, tumorigenesis, migration, and cell apoptosis. The inhibition of prostate cancer development by KIF15 knockdown was also assured in vivo. The Human Apoptosis Antibody Array showed that CD40L, cytoC, DR6, and p21 were up-regulated upon KIF15 knockdown, while IGF-I and Survivin were down-regulated. Moreover, the involvement of the PI3K/Akt pathway in the KIF15-mediated regulation of prostate cancer was preliminarily proved. In summary, KIF15 was identified to play an important role in the development or biological progress of prostate cancer and is considered to possess the potential to be used as a therapeutic target.

Targeting PI3K/Akt signaling in prostate cancer therapy

Urological cancers have obtained much attention in recent years due to their mortality and morbidity. The most common and malignant tumor of urological cancers is prostate cancer that imposes high socioeconomic costs on public life and androgen-deprivation therapy, surgery, and combination of chemotherapy and radiotherapy are employed in its treatment. PI3K/Akt signaling is an oncogenic pathway responsible for migration, proliferation and drug resistance in various cancers. In the present review, the role of PI3K/Akt signaling in prostate cancer progression is highlighted. The activation of PI3K/Akt signaling occurs in prostate cancer, while PTEN as inhibitor of PI3K/Akt shows down-regulation. Stimulation of PI3K/Akt signaling promotes survival of prostate tumor cells and prevents apoptosis. The cell cycle progression and proliferation rate of prostate tumor cells increase by PI3K/Akt signaling induction. PI3K/Akt signaling stimulates EMT and enhances metastasis of prostate tumor cells. Silencing PI3K/Akt signaling impairs growth and metastasis of prostate tumor cells. Activation of PI3K/Akt signaling mediates drug resistance and reduces radio-sensitivity of prostate tumor cells. Anti-tumor compounds suppress PI3K/Akt signaling in impairing prostate tumor progression. Furthermore, upstream regulators such as miRNAs, lncRNAs and circRNAs regulate PI3K/Akt signaling and it has clinical implications for prostate cancer patients.

Synthesis of novel sulphamethoxazole derivatives and exploration of their anticancer and antimicrobial properties

A series of new derivatives based on sulfamethoxazole were designed and synthesized in this study. The structures of the new compounds were confirmed based on a comprehensive characterization of spectral data by applied IR and ¹H as well as ¹³C NMR spectroscopy. The prepared compounds were tested for their anticancer and antimicrobial properties. Hydrazone 16b demonstrated convincing anticancer effect against all tested cell cultures such as human prostate carcinoma PPC-1 and human kidney carcinoma CaKi-1 cell lines, and human fibroblasts HF, n = 3. The most promising compound 16b showed higher activity against CaKi-1 cell line than the anticancer drugs axitinib and pazopanib used to treat renal cancer. Also, it was more active in the PPC-1 cell line compared to the approved PARP inhibitor Olaparib. Hydrazone 16b was also found to possess good antimicrobial properties against gram-positive bacteria strains of Staphylococcus aureus, Staphylococcus epidermidis, as well as Bacillus cereus.

A review of treatments targeting DNA-repair gene defects in metastatic castration resistant prostate cancer

Prostate cancer is the most common cancer in men. About 6% of those diagnosed will develop metastatic disease. Unfortunately, metastatic prostate cancer is fatal. Prostate cancer can be castration sensitive or castration resistant. Many treatments have been shown to improve progression free survival and overall survival in metastatic castration resistant prostate cancer (mCRPC). In recent years, studies have been exploring targeting mutations in the DNA Damage Repair (DDR) response that may amplify oncogenes. In this paper, we aim to discuss DDR, new approved targeted therapies, and the most recent clinical trials in the setting of metastatic CRPC.

Use of PARP inhibitors in prostate cancer: from specific to broader application

Prostate cancer (PC) is one of the major health issues of elderly men in the word. It is showed that there were approximately 1.414 million patients with PC in 2020 worldwide, with a high mortality rate in metastatic cases. In the present choices of treatment in PC, androgen deprivation therapy has long been as a backbone of them. But the clinical outcomes of patients with metastatic castration-resistant prostate cancer (mCRPC) were not ideal because of their poor prognosis, more effective therapeutic approaches are still necessary to further improve this problem. Poly (ADP-ribose) polymerase (PARP) inhibitors lead to the single-strand DNA breaks and/or double-strand DNA breaks, and result in synthetic lethality in cancer cells with impaired homologous recombination genes. It is estimated that approximately 20~25% of patients with mCRPC have a somatic or germinal DNA damage repair gene mutation. Furthermore, in "BRCAness" cases, which has been used to describe as tumors that have not arisen from a germline BRCA1 or BRCA2 mutation, there were also a number of studies sought to extend these promising results of PARP inhibitors. It is worth noting that an interaction between androgen receptor signaling and synthetic lethality with PARP inhibitors has been proposed. In this review, we discussed the mechanism of action and clinical research of PARP inhibitors, which may benefit population from "specific" to the "all-comer" in patients with PC when combined with novel hormonal therapies.

Androgen Receptor Splice Variants Contribute to the Upregulation of DNA Repair in Prostate Cancer

Background: Canonical androgen receptor (AR) signaling regulates a network of DNA repair genes in prostate cancer (PCA). Experimental and clinical evidence indicates that androgen deprivation not only suppresses DNA repair activity but is often synthetically lethal in combination with PARP inhibition. The present study aimed to elucidate the impact of AR splice variants (AR-Vs), occurring in advanced or late-stage PCA, on DNA repair machinery. Methods: Two hundred and seventy-three tissue samples were analyzed, including primary hormone-naïve PCA, primary metastases, hormone-sensitive PCA on androgen deprivation therapy (ADT) and castration refractory PCA (CRPC group). The transcript levels of the target genes were profiled using the nCounter platform. Experimental support for the findings was gained in AR/AR-V7-expressing LNCaP cells subjected to ionizing radiation. Results: AR-Vs were present in half of hormone-sensitive PCAs on androgen deprivation therapy (ADT) and two-thirds of CRPC samples. The presence of AR-Vs is highly correlated with increased activity in the AR pathway and DNA repair gene expression. In AR-V-expressing CRPC, the DNA repair score increased by 2.5-fold as compared to AR-V-negative samples. Enhanced DNA repair and the deregulation of DNA repair genes by AR-V7 supported the clinical data in a cell line model. Conclusions: The expression of AR splice variants such as AR-V7 in PCA patients following ADT might be a reason for reduced or absent therapy effects in patients on additional PARP inhibition due to the modulation of DNA repair gene expression. Consequently, AR-Vs should be further studied as predictive biomarkers for therapy response in this setting.

Traject3d allows label-free identification of distinct co-occurring phenotypes within 3D culture by live imaging

Single cell profiling by genetic, proteomic and imaging methods has expanded the ability to identify programmes regulating distinct cell states. The 3-dimensional (3D) culture of cells or tissue fragments provides a system to study how such states contribute to multicellular morphogenesis. Whether cells plated into 3D cultures give rise to a singular phenotype or whether multiple biologically distinct phenotypes arise in parallel is largely unknown due to a lack of tools to detect such heterogeneity. Here we develop Traject3d (Trajectory identification in 3D), a method for identifying heterogeneous states in 3D culture and how these give rise to distinct phenotypes over time, from label-free multi-day time-lapse imaging. We use this to characterise the temporal landscape of morphological states of cancer cell lines, varying in metastatic potential and drug resistance, and use this information to identify drug combinations that inhibit such heterogeneity. Traject3d is therefore an important companion to other single-cell technologies by facilitating real-time identification via live imaging of how distinct states can lead to alternate phenotypes that occur in parallel in 3D culture.

Cancer Cells Haploinsufficient for ATM Are Sensitized to PARP Inhibitors by MET Inhibition

The MET oncogene encodes a tyrosine kinase (TK) receptor. Its activation protects cells from death but also stimulates DNA damage response by triggering excess replicative stress. Transcriptomic classification of cancer cell lines based on MET expression showed that response to the PARP inhibitor (PARPi) olaparib is poorer in MET overexpressing cell lines. Accordingly, a high MET expressing lung carcinoma cell line was sensitized to PARPi by MET TK inhibition. This was not linked solely to MET overexpression: other MET overexpressing cell lines were biochemically but not functionally responsive to combined inhibition. Moreover, exogenously induced MET overexpression was unable to induce resistance to PARPi. The MET overexpressing cell line, responsive to the combined PARP and MET inhibition, carried a heterozygous mutation of the ATM gene and showed an attenuated response of ATM to PARPi. Among the downstream targets of ATM activation, NuMA was phosphorylated only in response to the combined PARP and MET inhibition. Given the role played by NuMA in mitosis, data show that the latter is affected by MET and PARP inhibition in cells with haploinsufficient ATM. This is important as ATM heterozygous mutation is frequently found in human cancer and in lung carcinomas in particular.