Combination of RAD001 (everolimus) and docetaxel reduces prostate and breast cancer cell VEGF production and tumour vascularisation independently of sphingosine-kinase-1

Assessments of prostate cancer cell functions highlight differences between a pan-PI3K/mTOR inhibitor, gedatolisib, and single-node inhibitors of the PI3K/AKT/mTOR pathway

Metastatic castration-resistant prostate cancer (mCRPC) is characterized by loss of androgen receptor (AR) sensitivity and oncogenic activation of the PI3K/AKT/mTOR (PAM) pathway. Loss of the PI3K regulator PTEN is frequent during prostate cancer (PC) initiation, progression, and therapeutic resistance. Co-targeting the PAM/AR pathways is a promising mCRPC treatment strategy but is hampered by reciprocal negative feedback inhibition or feedback relief. Most PAM inhibitors selectively spare (or weakly inhibit) one or more key nodes of the PAM pathway, potentiating drug resistance depending on the PAM pathway mutation status of patients. We posited that gedatolisib, a uniformly potent inhibitor of all class I PI3K isoforms, as well as mTORC1 and mTORC2, would be more effective than inhibitors targeting single PAM pathway nodes in PC cells. Using a combination of functional and metabolic assays, we evaluated a panel of PC cell lines with different PTEN/PIK3CA status for their sensitivity to multi-node PAM inhibitors (PI3K/mTOR: gedatolisib, samotolisib) and single-node PAM inhibitors (PI3Kα: alpelisib; AKT: capivasertib; mTOR: everolimus). Gedatolisib induced anti-proliferative and cytotoxic effects with greater potency and efficacy relative to the other PAM inhibitors, independent of PTEN/PIK3CA status. The superior effects of gedatolisib were likely associated with more effective inhibition of critical PAM-controlled cell functions, including cell cycle, survival, protein synthesis, oxygen consumption rate, and glycolysis. Our results indicate that potent and simultaneous blockade of all class I PI3K isoforms, mTORC1, and mTORC2 could circumvent PTEN-dependent resistance. Gedatolisib, as a single agent and in combination with other therapies, reported promising preliminary efficacy and safety in various solid tumor types. Gedatolisib is currently being evaluated in a Phase 1/2 clinical trial in combination with darolutamide in patients with mCRPC previously treated with an AR inhibitor, and in a Phase 3 clinical trial in combination with palbociclib and fulvestrant in patients with HR+/HER2- advanced breast cancer.

Synergistic Action of Benzyl Isothiocyanate and Sorafenib in a Nanoparticle Delivery System for Enhanced Triple-Negative Breast Cancer Treatment

Triple-negative breast cancer (TNBC) presents a therapeutic challenge due to its complex pathology and limited treatment options. Addressing this challenge, our study focuses on the effectiveness of combination therapy, which has recently become a critical strategy in cancer treatment, improving therapeutic outcomes and combating drug resistance and metastasis. We explored a novel combination therapy employing Benzyl isothiocyanate (BITC) and Sorafenib (SOR) and their nanoformulation, aiming to enhance therapeutic outcomes against TNBC. Through a series of in vitro assays, we assessed the cytotoxic effects of BITC and SOR, both free and encapsulated. The BITC-SOR-loaded nanoparticles (NPs) were synthesized using an amphiphilic copolymer, which demonstrated a uniform spherical morphology and favorable size distribution. The encapsulation efficiencies, as well as the sustained release profiles at varied pH levels, were quantified, revealing distinct kinetics that were well-modeled by the Korsmeyer-Peppas equation. The NP delivery system showed a marked dose-dependent cytotoxicity towards TNBC cells, with an IC50 of 7.8 μM for MDA-MB-231 cells, indicating improved efficacy over free drugs, while exhibiting minimal toxicity toward normal breast cells. Furthermore, the NPs significantly inhibited cell migration and invasion in TNBC models, surpassing the effects of free drugs. These findings underscore the potential of BITC-SOR-NPs as a promising therapeutic approach for TNBC, offering targeted delivery while minimizing systemic toxicity.

Prostate Cancer in Transplant Receivers-A Narrative Review on Oncological Outcomes

Prostate cancer (PCa) is a low tumor mutational burden (TMB) cancer with a poor response to immunotherapy. Nonetheless, immunotherapy can be useful, especially in metastatic castration-resistant PCa (mCRPC). Increased cytotoxic T lymphocytes (CTLs) density is correlated with a shorter overall survival (OS), an early biochemical relapse, and a generally poor PCa prognosis. An increased number of CCR4+ regulatory T cells (CCR4 + Tregs) relates to a higher Gleason score or earlier progression. The same therapeutic options are available for renal transplant recipients (RTRs) as for the population, with a comparable functional and oncological outcome. Radical retropubic prostatectomy (RRP) is the most common method of radical treatment in RTRs. Brachytherapy and robot-assisted radical prostatectomy (RARP) seem to be promising therapies. Further studies are needed to assess the need for prostatectomy in low-risk patients before transplantation. The rate of adverse pathological features in RTRs does not seem to differ from those observed in the non-transplant population and the achieved cancer control seems comparable. The association between PCa and transplantation is not entirely clear. Some researchers indicate a possible association between a more frequent occurrence of PCa and a worse prognosis in advanced or metastatic PCa. However, others claim that the risk and survival prognosis is comparable to the non-transplant population.

SOX2OT lncRNA Inhibition Suppresses the Stemness Characteristics of Esophageal Tumorspheres

BACKGROUND

SOX2OT is a novel cancer associated long non-coding RNA (LncRNA) with higher expression in variable tumor tissues, including esophageal squamous cell carcinoma (ESCC). It also plays an important function in embryonic neuronal development. Regarding its function in both stemness and carcinogenesis, here, we aimed to investigate its expression and function in tumorspheres of the esophagus using the RNAi method.

MATERIAL & METHODS

Two esophageal squamous cancer cells (ESCC): KYSE30 and YM1 cells were used for sphere enrichment. Cells were transfected with SOX2OT targeting and control siRNA. The size and the number of spheres were measured using light microscopy. Gene expression of the pluripotency genes was measured by qRT-PCR and docetaxel chemoresistance was assessed by MTS viability assay.

RESULTS

Our findings showed that ESCC tumorspheres overexpress SOX2OT gene along with other stemness genes (SOX2, OCT4A, and Nanog) compared to their original cancer cells. RNAi experiments indicated that SOX2OT knockdown can suppress the stemness-related gene expression, sphere formation ability (both size and number), and docetaxel resistance as three of the main cancer stem cell characteristics of tumorspheres.

CONCLUSION

Altogether our results showed the regulatory role of SOX2OT in pluripotency and stemness in ESCC tumorspheres. Our results suggest a potential application of SOX2OT inhibition in combination with docetaxel for ESCC inhibition in vitro.

From Therapy Resistance to Targeted Therapies in Prostate Cancer

Prostate cancer (PCa) is the second most common malignancy among men worldwide. Although early-stage disease is curable, advanced stage PCa is mostly incurable and eventually becomes resistant to standard therapeutic options. Different genetic and epigenetic alterations are associated with the development of therapy resistant PCa, with specific players being particularly involved in this process. Therefore, identification and targeting of these molecules with selective inhibitors might result in anti-tumoral effects. Herein, we describe the mechanisms underlying therapy resistance in PCa, focusing on the most relevant molecules, aiming to enlighten the current state of targeted therapies in PCa. We suggest that selective drug targeting, either alone or in combination with standard treatment options, might improve therapeutic sensitivity of resistant PCa. Moreover, an individualized analysis of tumor biology in each PCa patient might improve treatment selection and therapeutic response, enabling better disease management.

Heterogeneity and Cancer-Related Features in Lymphangioleiomyomatosis Cells and Tissue

Lymphangioleiomyomatosis (LAM) is a rare, low-grade metastasizing disease characterized by cystic lung destruction. LAM can exhibit extensive heterogeneity at the molecular, cellular, and tissue levels. However, the molecular similarities and differences among LAM cells and tissue, and their connection to cancer features are not fully understood. By integrating complementary gene and protein LAM signatures, and single-cell and bulk tissue transcriptome profiles, we show sources of disease heterogeneity, and how they correspond to cancer molecular portraits. Subsets of LAM diseased cells differ with respect to gene expression profiles related to hormones, metabolism, proliferation, and stemness. Phenotypic diseased cell differences are identified by evaluating lumican (LUM) proteoglycan and YB1 transcription factor expression in LAM lung lesions. The RUNX1 and IRF1 transcription factors are predicted to regulate LAM cell signatures, and both regulators are expressed in LAM lung lesions, with differences between spindle-like and epithelioid LAM cells. The cancer single-cell transcriptome profiles most similar to those of LAM cells include a breast cancer mesenchymal cell model and lines derived from pleural mesotheliomas. Heterogeneity is also found in LAM lung tissue, where it is mainly determined by immune system factors. Variable expression of the multifunctional innate immunity protein LCN2 is linked to disease heterogeneity. This protein is found to be more abundant in blood plasma from LAM patients than from healthy women. IMPLICATIONS: This study identifies LAM molecular and cellular features, master regulators, cancer similarities, and potential causes of disease heterogeneity.

Computational modeling identifies multitargeted kinase inhibitors as effective therapies for metastatic, castration-resistant prostate cancer

Metastatic, castration-resistant prostate cancer (mCRPC) is an advanced prostate cancer with limited therapeutic options and poor patient outcomes. To investigate whether multitargeted kinase inhibitors (KIs) represent an opportunity for mCRPC drug development, we applied machine learning–based functional screening and identified two KIs, PP121 and SC-1, which demonstrated strong suppression of CRPC growth in vitro and in vivo. Furthermore, we show the marked ability of these KIs to improve on standard-of-care chemotherapy in both tumor response and survival, suggesting that combining multitargeted KIs with chemotherapy represents a promising avenue for mCRPC treatment. Overall, our findings demonstrate the application of a multidisciplinary strategy that blends bench science with machine-learning approaches for rapidly identifying KIs that result in desired phenotypic effects.

Castration-resistant prostate cancer (CRPC) is an advanced subtype of prostate cancer with limited therapeutic options. Here, we applied a systems-based modeling approach called kinome regularization (KiR) to identify multitargeted kinase inhibitors (KIs) that abrogate CRPC growth. Two predicted KIs, PP121 and SC-1, suppressed CRPC growth in two-dimensional in vitro experiments and in vivo subcutaneous xenografts. An ex vivo bone mimetic environment and in vivo tibia xenografts revealed resistance to these KIs in bone. Combining PP121 or SC-1 with docetaxel, standard-of-care chemotherapy for late-stage CRPC, significantly reduced tibia tumor growth in vivo, decreased growth factor signaling, and vastly extended overall survival, compared to either docetaxel monotherapy. These results highlight the utility of computational modeling in forming physiologically relevant predictions and provide evidence for the role of multitargeted KIs as chemosensitizers for late-stage, metastatic CRPC.

Metformin Potentiates the Anticancer Effect of Everolimus on Cervical Cancer In Vitro and In Vivo

Simple Summary

Recent studies have shown that metformin combined with clinical chemotherapeutic drugs could cause decreased cell toxicity and attenuate tumor resistance in various types of cancer. The aim of the present study was to elucidate whether combined treatment with metformin and everolimus has a synergistic anticancer effect in human cervical cancer in vitro and in vivo. The results showed that this combined treatment synergistically inhibited the growth of human cervical cancer cell lines and xenografts in nude mice, and induced caspase-dependent apoptosis, promoting sub-G1- and G0/G1-phase arrest and enhancing mtROS production. Combined treatment also synergistically inactivated PI3K/AKT signaling and activated MAPKs signaling in cervical cancer. Our data suggested that metformin potentiates the anticancer effect of everolimus on cervical cancer, and combined treatment provides a novel therapeutic strategy for patients with cervical cancer.

Abstract

Cervical cancer is globally the fourth most common cancer in women. Metformin is a widely used drug for the treatment of type II diabetes and has been shown to possess important anticancer properties in cervical cancer. Everolimus is an mTOR inhibitor and is widely used to treat NETs, RCC, TSC, and breast cancers. The present study investigated the anticancer effects of metformin and everolimus in cervical cancer, when used alone or in combination. CaSki and C33A human cervical cancer cells were treated with different concentrations of everolimus alone or in combination with metformin. Cell viability was assessed using a CCK-8 assay. Cell apoptosis, cell-cycle, and mtROS analyses were conducted using flow cytometry. Target protein levels were analyzed by Western blotting. Related mechanisms were confirmed using appropriate inhibitors (z-VAD-fmk and BIRB796). The in vitro results were further confirmed in a xenograft tumor study. Both metformin and everolimus, when used alone, were moderately effective in inhibiting cell proliferation and inducing cell apoptosis of CaSki and C33A cells. When used in combination, these two drugs synergistically inhibited the growth of human cervical cancer cells and xenografts in nude mice, promoted sub-G1- and G0/G1-phase cell-cycle arrest, and enhanced mtROS production. The protein expressions of PI3K (p110α) and p-AKT were significantly downregulated, while P27, P21, p-p38, p-ERK, and p-JNK were upregulated following combined treatment. These results revealed that metformin potentiates the anticancer effect of everolimus on cervical cancer, and combination treatment with metformin and everolimus provides a novel therapeutic strategy for patients with cervical cancer.

Inhibitors of the PI3K/Akt/mTOR Pathway in Prostate Cancer Chemoprevention and Intervention

The phosphatidylinositol 3-kinase (PI3K)/serine-threonine kinase (Akt)/mammalian target of the rapamycin (mTOR)-signaling pathway has been suggested to have connections with the malignant transformation, growth, proliferation, and metastasis of various cancers and solid tumors. Relevant connections between the PI3K/Akt/mTOR pathway, cell survival, and prostate cancer (PC) provide a great therapeutic target for PC prevention or treatment. Recent studies have focused on small-molecule mTOR inhibitors or their usage in coordination with other therapeutics for PC treatment that are currently undergoing clinical testing. In this study, the function of the PI3K/Akt/mTOR pathway, the consequence of its dysregulation, and the development of mTOR inhibitors, either as an individual substance or in combination with other agents, and their clinical implications are discussed. The rationale for targeting the PI3K/Akt/mTOR pathway, and specifically the application and potential utility of natural agents involved in PC treatment is described. In addition to the small-molecule mTOR inhibitors, there are evidence that several natural agents are able to target the PI3K/Akt/mTOR pathway in prostatic neoplasms. These natural mTOR inhibitors can interfere with the PI3K/Akt/mTOR pathway through multiple mechanisms; however, inhibition of Akt and suppression of mTOR 1 activity are two major therapeutic approaches. Combination therapy improves the efficacy of these inhibitors to either suppress the PC progression or circumvent the resistance by cancer cells.

RAD001 targeted HUVECs reverses 12-lipoxygenase-induced angiogenesis in oesophageal squamous cell carcinoma

12‐LOX plays an important role in the progression of various malignancies. However, the underlying mechanisms of the action of 12‐LOX and tumour treatment strategies remain not fully defined. In this study, we investigated the possible roles of 12‐LOX in ESCC and explored the new therapeutic target. Approximately 73% of ESCC tissues showed marked up‐regulation of 12‐LOX, which was associated with poor prognosis. 12‐LOX overexpression was positively correlated with the malignant progression of ESCC as demonstrated both in vitro and in vivo. Up‐regulation of 12‐LOX significantly increased the proliferation of ESCC cells and the xenograft volume. Moreover, 12‐LOX up‐regulation promoted tube formation of HUVECs and tumour angiogenesis in xenografts. Mechanism investigation indicated that 12‐LOX overexpression led to activation of the PI3K/AKT/mTOR pathway and the up‐regulation of VEGF in ESCC cells. Subsequent analysis indicated that the RAD001 could reverse the 12‐LOX‐induced promoting effect on ESCC. Specifically, the application of RAD001 inhibited the proliferation of ESCC cells and the tube‐forming ability of HUVECs. In the drug group, the xenografts exhibited significant volume reduction and angiogenesis inhibition. We demonstrated that RAD001 could inhibit HUVEC migration. These findings presented the evidence that RAD001 had distinct roles on HUVECs and could exert anti‐tumour effects by targeting not only the PI3K/AKT/mTOR pathway but the angiogenesis in ESCC.

The Tumorigenic Effect of Sphingosine Kinase 1 and Its Potential Therapeutic Target

Sphingosine kinase 1 (SPHK1) regulates cell proliferation and survival by converting sphingosine to the signaling mediator sphingosine 1-phosphate (S1P). SPHK1 is widely overexpressed in most cancers, promoting tumor progression and is associated with clinical prognosis. Numerous studies have explored SPHK1 as a promising target for cancer therapy. However, due to insufficient knowledge of SPHK1 oncogenic mechanisms, its inhibitors’ therapeutic potential in preventing and treating cancer still needs further investigation. In this review, we summarized the metabolic balance regulated by the SPHK1/S1P signaling pathway and highlighted the oncogenic mechanisms of SPHK1 via the upregulation of autophagy, proliferation, and survival, migration, angiogenesis and inflammation, and inhibition of apoptosis. Drug candidates targeting SPHK1 were also discussed at the end. This review provides new insights into the oncogenic effect of SPHK1 and sheds light on the future direction for targeting SPHK1 as cancer therapy.

Sphingosine Kinase 1 in Breast Cancer-A New Molecular Marker and a Therapy Target

It is now well-established that sphingosine kinase 1 (SK1) plays a significant role in breast cancer development, progression, and spread, whereas SK1 knockdown can reverse these processes. In breast cancer cells and tumors, SK1 was shown to interact with various pathways involved in cell survival and chemoresistance, such as nuclear factor-kappa B (NFκB), Notch, Ras/MAPK, PKC, and PI3K. SK1 is upregulated by estrogen signaling, which, in turn, confers cancer cells with resistance to tamoxifen. Sphingosine-1-phosphate (S1P) produced by SK1 has been linked to tumor invasion and metastasis. Both SK1 and S1P are closely linked to inflammation and adipokine signaling in breast cancer. In human tumors, high SK1 expression has been linked with poorer survival and prognosis. SK1 is upregulated in triple negative tumors and basal-like subtypes. It is often associated with high phosphorylation levels of ERK1/2, SFK, LYN, AKT, and NFκB. Higher tumor SK1 mRNA levels were correlated with poor response to chemotherapy. This review summarizes the up-to-date evidence and discusses the therapeutic potential for the SK1 inhibition in breast cancer, with emphasis on the mechanisms of chemoresistance and combination with other therapies such as gefitinib or docetaxel. We have outlined four key areas for future development, including tumor microenvironment, combination therapies, and nanomedicine. We conclude that SK1 may have a potential as a target for precision medicine, its high expression being a negative prognostic marker in ER-negative breast cancer, as well as a target for chemosensitization therapy.

Heparanase Inhibition by Pixatimod (PG545): Basic Aspects and Future Perspectives

Pixatimod is an inhibitor of heparanase, a protein which promotes cancer via its regulation of the extracellular environment by enzymatic cleavage of heparan sulfate (HS) and non-enzymatic signaling. Through its inhibition of heparanase and other HS-binding signaling proteins, pixatimod blocks a number of pro-cancerous processes including cell proliferation, invasion, metastasis, angiogenesis and epithelial-mesenchymal transition. Several laboratories have found that these activities have translated into potent activity using a range of different mouse cancer models, including approximately 30 xenograft and 20 syngeneic models. Analyses of biological samples from these studies have confirmed the heparanase targeting of this agent in vivo and the broad spectrum of anti-cancer effects that heparanase blockade achieves. Pixatimod has been tested in combination with a number of approved anti-cancer drugs demonstrating its clinical potential, including with gemcitabine, paclitaxel, sorafenib, platinum agents and an anti-PD-1 antibody. Clinical testing has shown pixatimod to be well tolerated as a monotherapy, and it is currently being investigated in combination with the anti-PD-1 drug nivolumab in a pancreatic cancer phase I trial.

Intratumoral Heterogeneity Determines the Expression of mTOR-pathway Proteins in Prostate Cancer

The aim of this study was to evaluate the expression of mammalian target of rapamycin (mTOR), phosphorylated-mTOR (p-mTOR), and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) in prostate cancer (PCa) in order to assess intratumoral heterogeneity and correlation with clinicopathological parameters. Tissue samples from 115 patients undergoing radical prostatectomy were included in a tissue microarray comprising (A) tissue from the tumor center, (B) malignant border of the tumor, (C) tumor-adjacent benign tissue, and (D) tumor-distant benign prostatic tissue. Immune reactive scores 0-12 were correlated with clinical data in reference to localization. A meta-analysis of studies investigating the association between biochemical recurrence (BCR) and parameters of the mTOR pathway was conducted. Regardless of the location within the tumor, cancer tissue showed higher expression of mTOR, p-mTOR, and 4EB-P1 compared to benign tissue (p < 0.01). Significant differences in expression between tissue samples from groups C and D were observed for mTOR and p-mTOR. When considering expression according to the pathological stage, we observed lower p-mTOR expression in pT3 vs. pT2 (7.9 and 6.3; p = 0.01). After a median follow-up of 74.5 months (IQR 65.0-84.0), 27 patients (23.47%) developed BCR. Weak staining of mTOR was associated with shorter time to BCR (HR: 2.0; p = 0.049) after correcting for PSA and T stage. However, a significant association of mTOR expression with BCR was found for specimens from the malignant border of the tumor (B) but not the tumor center (A) (p = 0.0034 log rank). In a meta-analysis, we found that the expressions of mTOR ((RR) = 0.70; 95% CI 0.43-1.12; p = 0.13) and 4E-BP1 ((RR) = 0.86; p = 0.53) were not statistically associated with BCR, while strong staining of p-mTOR was associated with a lower risk of BCR ((RR) = 0.57; p = 0.002). All 3 markers showed stronger expression in PCa and exhibited local gradients in relation to the border of tumor and healthy tissue. Our results suggest an important role of intratumor heterogeneity for the use of mTOR parameters as biomarkers in PCa.

Synchronous inhibition of mTOR and VEGF/NRP1 axis impedes tumor growth and metastasis in renal cancer

Clear cell renal cell carcinoma (ccRCC) is known for its highly vascular phenotype which is associated with elevated expression of vascular endothelial growth factor A (VEGF), also known as vascular permeability factor (VPF). Accordingly, VEGF has been an attractive target for antiangiogenic therapies in ccRCC. Two major strategies have hitherto been utilized for VEGF-targeted antiangiogenic therapies: targeting VEGF by antibodies, ligand traps or aptamers, and targeting the VEGF receptor signaling via antibodies or small-molecule tyrosine-kinase inhibitors (TKIs). In the present article we utilized two entirely different approaches: targeting mammalian target of rapamycin (mTOR) pathway that is known to be involved in VEGF synthesis, and disruption of VEGF/Neuroplin-1 (NRP1) axis that is known to activate proangiogenic and pro-tumorigenic signaling in endothelial and tumor cells, respectively. Everolimus (E) and a small-molecule inhibitor EG00229 (G) were used for the inhibition of mTOR and the disruption of VEGF/NRP1 axis, respectively. We also exploited a liposomal formulation decorated with a proprietary tumor-targeting-peptide (TTP) to simultaneously deliver these two agents in a tumor-targeted manner. The TTP-liposomes encapsulating both Everolimus and EG00229 (EG-L) demonstrated higher in vitro and in vivo growth retardation than the single drug-loaded liposomes (E-L and G-L) in two different ccRCC models and led to a noticeable reduction in lung metastasis in vivo. In addition, EG-L displayed remarkable inhibition of tumor growth in a highly aggressive syngeneic immune-competent mouse model of ccRCC developed in Balb/c mice. Taken together, this study demonstrates an effective approach to achieve improved therapeutic outcome in ccRCC.

Co-delivery of everolimus and vinorelbine via a tumor-targeted liposomal formulation inhibits tumor growth and metastasis in RCC

Background

Renal cell carcinoma (RCC) is notorious for its resistance towards chemotherapy and radiation therapy in general. Combination therapy is often helpful in alleviating the resistance mechanisms by targeting multiple signaling pathways but is usually more toxic than monotherapy. Co-encapsulation of multiple therapeutic agents in a tumor-targeted drug delivery platform is a promising strategy to mitigate these limitations.

Methods

A tumor-targeted liposomal formulation was prepared using phospholipids, cholesterol, DSPE-(PEG)₂₀₀₀-OMe and a proprietary tumor-targeting-peptide (TTP)-conjugated lipopeptide. An efficient method was optimized to encapsulate everolimus and vinorelbine in this liposomal formulation. Single drug-loaded liposomes were also prepared for comparison. Finally, the drug-loaded liposomes were tested in vitro and in vivo in two different RCC cell lines.

Results

The tumor-targeted liposomal formulation demonstrated excellent tumor-specific uptake. The dual drug-loaded liposomes exhibited significantly higher growth inhibition in vitro compared to the single drug-loaded liposomes in two different RCC cell lines. Similarly, the dual drug-loaded liposomes demonstrated significantly higher suppression of tumor growth compared to the single drug-loaded liposomes in two different subcutaneous RCC xenografts. In addition, the dual drug-loaded liposomes instigated significant reduction in lung metastasis in those experiments.

Conclusion

Taken together, this study demonstrates that co-delivery of everolimus and vinorelbine with a tumor-targeted liposomal formulation is an effective approach to achieve improved therapeutic outcome in RCC.

The combination of everolimus and terameprocol exerts synergistic antiproliferative effects in endometrial cancer: molecular role of insulin-like growth factor binding protein 2

Oncogenic PIK3CA mutations are common in endometrial cancers, and the PI3K/AKT/mTOR pathway is targetable by drugs. We sought to investigate whether the combination of an mTOR inhibitor, everolimus (RAD001), and an AKT inhibitor, terameprocol (M4N), exerts better antiproliferative effects in endometrial cancer. The molecular mechanisms underlying their pharmacological action were also examined. The combination of RAD001 and M4N exerted in vitro synergistic effects on cell viability, apoptosis, and expression of IGFBP2 in endometrial cancer cells. Mechanistically, the Sp1 site on the IGFBP2 promoter was required for RAD001- and M4N-induced downregulation. IGFBP2 protein expression was higher in endometrial cancer than in the normal endometrium (P < 0.001). Furthermore, elevated IGFBP2 histoscores were significantly associated with a lower overall survival (P = 0.021). In conclusion, our in vitro results demonstrate that RAD001 and M4N exert synergistic antiproliferative effects against endometrial cancer cells, which appeared to be mediated by the inhibition of IGFBP2, a key anti-apoptotic regulator. Further clinical studies of this drug combination in patients with endometrial cancer may be warranted, especially in the presence of PIK3CA and IGFBP2 aberrations. KEY MESSAGES: RAD001 and M4N synergistically suppress endometrial cancer growth. IGFBP2 is overexpressed in endometrial cancer. The combination of RAD001 and M4N significantly reduces IGFBP2 overexpression. Sp1 binding site on the IGFBP2 promoter is required for RAD001- and M4N-induced downregulation. High IGFBP2 histoscore in endometrial cancer portends a poor prognosis.

Combination therapy Eve and Pac to induce apoptosis in cervical cancer cells by targeting PI3K/AKT/mTOR pathways

This study aimed to investigate the anti-cervical cancer effects of everolimus (Eve) and paclitaxel (Pac) when used alone or in combination. Human cervical cancer cells HeLa and SiHa were divided into four group: Blank control group (control), everolimus group (Eve), paclitaxel group (Pac) and combined therapy group (Eve + Pac). The cell viability was detected by CCK-8 assay and the cell cloning ability was detected by clonegenic assay. Flow cytometry was used to detect cell apoptosis. Meanwhile, the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR) and their phosphorylated proteins were studied by western blot. The HeLa and SiHa cells proliferation and cloning ability were significantly inhibited in drug treatment groups compared with control group (p < .05), and the Eve + Pac combinatorial therapy showed the better results than single treatment with Eve or Pac. Combination of Eve and Pac has synergistic effect on the induction of apoptosis in cervical cancer cells. In addition, the protein ratios in HeLa and SiHa cell treated with the Eve + Pac combination were significantly lower than that of cervical cancer cells treated with either Eve or Pac cell alone. Our study suggested that Eve + Pac provide a novel therapeutic strategy for cervical cancer.

Field template-based design and biological evaluation of new sphingosine kinase 1 inhibitors

Purpose

Sphingosine kinase 1 (SK1) is a protooncogenic enzyme expressed in many human tumours and is associated with chemoresistance and poor prognosis. It is a potent therapy target and its inhibition chemosensitises solid tumours. Despite recent advances in SK1 inhibitors synthesis and validation, their clinical safety and chemosensitising options are not well described. In this study, we have designed, synthesised and tested a new specific SK1 inhibitor with a low toxicity profile.

Methods

Field template molecular modelling was used for compound design. Lead compounds were tested in cell and mouse cancer models.

Results

Field template analysis of three known SK1 inhibitors, SKI-178, 12aa and SK1-I, was performed and compound screening identified six potential new SK1 inhibitors. SK1 activity assays in both cell-free and in vitro settings showed that two compounds were effective SK1 inhibitors. Compound SK-F has potently decreased cancer cell viability in vitro and sensitised mouse breast tumours to docetaxel (DTX) in vivo, without significant whole-body toxicity.

Conclusion

Through field template screening, we have identified a new SK1 inhibitor, SK-F, which demonstrated antitumour activity in vitro and in vivo without overt toxicity when combined with DTX.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-4900-1) contains supplementary material, which is available to authorized users.

Expression of microRNA-99a-3p in Prostate Cancer Based on Bioinformatics Data and Meta-Analysis of a Literature Review of 965 Cases

BACKGROUND microRNAs (miRNAs) have a role as biomarkers in human cancer. The aim of this study was to use bioinformatics data, and review of cases identified from the literature, to investigate the role of microRNA-99a-3p (miR-99a-3p) in prostate cancer, including the identification of its target genes and signaling pathways. MATERIAL AND METHODS Meta-analysis from a literature review included 965 cases of prostate cancer. Bioinformatics databases interrogated for miR-99a-3p in prostate cancer included The Cancer Genome Atlas (TCGA), the Gene Expression Omnibus (GEO), and ArrayExpress. Twelve computational predictive algorithms were developed to integrate miR-99a-3p target gene prediction data. Bioinformatics analysis data from Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) network analysis were used investigate the possible pathways and target genes for miR-99a-3p in prostate cancer. RESULTS TCGA data showed that miR-99a was down-regulated in prostate cancer when compared with normal prostate tissue. Receiver-operating characteristic (ROC) curve area under the curve (AUC) for miR-99a-3p was 0.660 (95% CI, 0.587-0.732) or a moderate level of discriminations. Pathway analysis showed that miR-99a-3p was associated with the Wnt and vascular endothelial growth factor (VEGF) signaling pathways. The PPP3CA and HYOU1 genes, selected from the PPI network, were highly expressed in prostate cancer tissue compared with normal prostate tissue, and negatively correlated with the expression of miR-99a-3p. CONCLUSIONS In prostate cancer, miR-99a-3p expression was associated with the Wnt and VEGF signaling pathways, which might inhibit the expression of PPP3CA or HYOU1.

Synergistic effects and mechanisms of impressic acid or acankoreanogein in combination with docetaxel on prostate cancer

Prostate cancer (PCa) is a common cancer among males and a leading cause of cancer deaths.

Protein Kinase Targets in Breast Cancer

With 1.67 million new cases and 522,000 deaths in the year 2012, breast cancer is the most common type of diagnosed malignancy and the second leading cause of cancer death in women around the world. Despite the success of screening programs and the development of adjuvant therapies, a significant percentage of breast cancer patients will suffer a metastatic disease that, to this day, remains incurable and justifies the research of new therapies to improve their life expectancy. Among the new therapies that have been developed in recent years, the emergence of targeted therapies has been a milestone in the fight against cancer. Over the past decade, many studies have shown a causal role of protein kinase dysregulations or mutations in different human diseases, including cancer. Along these lines, cancer research has demonstrated a key role of many protein kinases during human tumorigenesis and cancer progression, turning these molecules into valid candidates for new targeted therapies. The subsequent discovery and introduction in 2001 of the kinase inhibitor imatinib, as a targeted treatment for chronic myelogenous leukemia, revolutionized cancer genetic pathways research, and lead to the development of multiple small-molecule kinase inhibitors against various malignancies, including breast cancer. In this review, we analyze studies published to date about novel small-molecule kinase inhibitors and evaluate if they would be useful to develop new treatment strategies for breast cancer patients.