Reversal of paclitaxel resistance in human ovarian cancer cells with redox-responsive micelles consisting of α-tocopheryl succinate-based polyphosphoester copolymers

Co-delivery of Paclitaxel/Atovaquone/Quercetin to regulate energy metabolism to reverse multidrug resistance in ovarian cancer by PLGA-PEG nanoparticles

Ovarian cancer is a malignant tumor that seriously endangers the lives of women, with chemotherapy being the primary clinical treatment. However, chemotherapy encounters the problem of generating multidrug resistance (MDR), mainly due to drug efflux induced by P-glycoprotein (P-gp), which decreases intracellular accumulation of chemotherapeutic drugs. The drugs efflux mediated by P-gp requires adenosine triphosphate (ATP) hydrolysis to provide energy. Therefore, modulating energy metabolism pathways and inhibiting ATP production may be a potential strategy to reverse MDR. Herein, we developed a PTX-ATO-QUE nanoparticle (PAQNPs) based on a PLGA-PEG nanoplatform capable of loading the mitochondrial oxidative phosphorylation (OXPHOS) inhibitor atovaquone (ATO), the glycolysis inhibitor quercetin (QUE), and the chemotherapeutic drug paclitaxel (PTX) to reverse MDR by inhibiting energy metabolism through multiple pathways. Mechanistically, PAQNPs could effectively inhibit the OXPHOS and glycolytic pathways of A2780/Taxol cells by suppressing the activities of mitochondrial complex III and hexokinase II (HK II), respectively, ultimately decreasing intracellular ATP levels in tumor cells. Energy depletion can effectively inhibit cell proliferation and reduce P-gp activity, increasing the chemotherapeutic drug PTX accumulation in the cells. Moreover, intracellular reactive oxygen species (ROS) is increased with PTX accumulation and leads to chemotherapy-resistant cell apoptosis. Furthermore, PAQNPs significantly inhibited tumor growth in the A2780/Taxol tumor-bearing NCG mice model. Immunohistochemical (IHC) analysis of tumor tissues revealed that P-gp expression was suppressed, demonstrating that PAQNPs are effective in reversing MDR in tumors by inducing energy depletion. In addition, the safety study results, including blood biochemical indices, major organ weights, and H&E staining images, showed that PAQNPs have a favorable in vivo safety profile. In summary, the results suggest that the combined inhibition of the two energy pathways, OXPHOS and glycolysis, can enhance chemotherapy efficacy and reverse MDR in ovarian cancer.

Synergistic Sensitization of High-Grade Serous Ovarian Cancer Cells Lacking Caspase-8 Expression to Chemotherapeutics Using Combinations of Small-Molecule BRD4 and CDK9 Inhibitors

Ovarian cancer is one of the most lethal gynecological cancers worldwide, with approximately 70% of cases diagnosed in advanced stages. This late diagnosis results from the absence of early warning symptoms and is associated with an unfavorable prognosis. A standard treatment entails a combination of primary chemotherapy with platinum and taxane agents. Tumor recurrence following first-line chemotherapy with Carboplatin and Paclitaxel is detected in 80% of advanced ovarian cancer patients, with disease relapse occurring within 2 years of initial treatment. Platinum-resistant ovarian cancer is one of the biggest challenges in treating patients. Second-line treatments involve PARP or VEGF inhibitors. Identifying novel biomarkers and resistance mechanisms is critical to overcoming resistance, developing newer treatment strategies, and improving patient survival. In this study, we have determined that low Caspase-8 expression in ovarian cancer patients leads to poor prognosis. High-Grade Serous Ovarian Cancer (HGSOC) cells lacking Caspase-8 expression showed an altered composition of the RNA Polymerase II-containing transcriptional elongation complex leading to increased transcriptional activity. Caspase-8 knockout cells display increased BRD4 expression and CDK9 activity and reduced sensitivities to Carboplatin and Paclitaxel. Based on our work, we are proposing three potential therapeutic approaches to treat advanced ovarian cancer patients who exhibit low Caspase-8 expression and resistance to Carboplatin and/or Paclitaxel-combinations of (1) Carboplatin with small-molecule BRD4 inhibitors; (2) Paclitaxel with small-molecule BRD4 inhibitors, and (3) small-molecule BRD4 and CDK9 inhibitors. In addition, we are also proposing two predictive markers of chemoresistance-BRD4 and pCDK9.

Design, synthesis and bioactivity investigation of peptide-camptothecin conjugates as anticancer agents with a potential to overcome drug resistance

Camptothecin (CPT) is a natural plant alkaloid from Camptotheca that exhibits a potent anticancer activity. However, its continued utilization is hindered by drawbacks such as low water solubility and restricted tumor selectivity. Cationic anticancer peptides (CAPs) are generally soluble in water, and exhibit favorable selectivity against malignant cells. In previous study, we have reported a CAP termed KM8-Aib present conspicuous selective anticancer effect. Thus, it is postulated conjugating KM8-Aib with CPT might be a plausible approach to improve the defects of CPT. A series of peptide-CPT conjugates were synthesized and subjected to biological evaluation. Among these compounds, Kb-CC07 displayed the highest selective activity against a set of cancer cell lines including drug-resistant cells, showing the IC50 values in the 0.11-1.01 μM range which is 1.9-22.6 times better than that of CPT, and a wide therapeutic index of 124.5 (vs 5.3 for CPT). The water solubility of Kb-CC07 was also improved by ∼ 100 fold compared with CPT. Further investigation unraveled that Kb-CC07 could effectively penetrate across plasma membranes and delivered more CPT molecules into cancer cells, overcoming the drug-resistance result from efflux drug transporters on tumor surface. In vivo experiments supported that Kb-CC07 has excellent in vivo antiproliferative activity against drug-resistant tumors over CPT (tumor growth inhibition of 98.2% and 37.5% for Kb-CC07 and CPT, respectively, at 5 μmol·kg-1), and prompts CPT accumulation in tumor tissue rather than normal organs, thus producing limited toxicities. To sum up, coupling therapeutic agents to CAPs would be a potential strategy to conquer the shortcomings of anticancer drugs. Additionally, Kb-CC07 is suggested to be a promising anticancer candidate deserving further investigation.

Progesterone-Cationic Lipid Conjugate-Based Self-Aggregates for Cancer Cell-Selective Uptake through Macropinocytosis and the Antitumour Effect

Progesterone (PR) is an endogenous steroid hormone that activates the progesterone receptor (PgR) and is known to play a critical role in cancer progression. Herein, we report the development of cationic lipid-conjugated PR derivatives by covalently conjugating progesterone with cationic lipids of varying hydrocarbon chain lengths (n = 6-18) through a succinate linker. Cytotoxicity studies performed on eight different cancer cell lines reveal that PR10, one of the lead derivatives, exerts notable toxicity (IC₅₀ = 4-12 μM) in cancer cells irrespective of their PgR expression status and remains largely nontoxic to noncancerous cells. Mechanistic studies show that PR10 induces G2/M-phase cell cycle arrest in cancer cells, leading to apoptosis and cell death by inhibiting the PI3K/AKT cell survival pathway and p53 upregulation. Further, in vivo study shows that PR10 treatment significantly reduces melanoma tumor growth and prolongs the overall survival of melanoma tumor-bearing C57BL/6J mice. Interestingly, PR10 readily forms stable self-aggregates of ∼190 nm size in an aqueous environment and exhibits selective uptake into cancerous cell lines. In vitro uptake mechanism studies in various cell lines (cancerous cell lines B16F10, MCF7, PC3, and noncancerous cell line HEK293) using endocytosis inhibition proves that PR10 nanoaggregates enter selectively into the cancer cells predominantly using macropinocytosis and/or caveolae-mediated endocytosis. Overall, this study highlights the development of a self-aggregating cationic derivative of progesterone with anticancer activity, and its cancer cell-selective accumulation in nanoaggregate form holds great potential in the field of targeted drug delivery.

Current Update on Nanotechnology-Based Approaches in Ovarian Cancer Therapy

Ovarian cancer is one of the leading causes of cancer-related deaths among women. The drawbacks of conventional therapeutic strategies encourage researchers to look for alternative strategies, including nanotechnology. Nanotechnology is one of the upcoming domains of science that is rechanneled towards targeted cancer therapy and diagnosis. Nanocarriers such as dendrimers, liposomes, polymer micelles, and polymer nanoparticles present distinct surface characteristics in morphology, surface chemistry, and mode of action that help differentiate normal and malignant cells, which paves the way for target-specific drug delivery. Similarly, nanoparticles have been strategically utilized as efficacious vehicles to deliver drugs that alter the epigenetic modifications in epigenetic therapy. Some studies suggest that the use of specialized target-modified nanoparticles in siRNA-based nanotherapy prevents internalization and improves the antitumor activity of siRNA by ensuring unrestrained entry of siRNA into the tumor vasculature and efficient intracellular delivery of siRNA. Moreover, research findings highlight the significance of utilizing nanoparticles as depots for photosensitive drugs in photodynamic therapy. The applicability of nanoparticles is further extended to medical imaging. They serve as contrast agents in combination with conventional imaging modalities such as MRI, CT, and fluorescence-based imaging to produce vivid and enhanced images of tumors. Therefore, this review aims to explore and delve deeper into the advent of various nanotechnology-based therapeutic and imaging techniques that provide non-invasive and effective means to tackle ovarian cancers.

Modification of α-Tocopherol Succinate with a Tumor-targeting Peptide Conjugate Enhances the Antitumor Efficacy of a Paclitaxel-loaded Lipid Aggregate

Paclitaxel (PTX) is a widely used chemotherapeutic agent in the clinic. However, its clinical benefit is limited due to its low water solubility, off-target toxicity, and for being a multidrug-resistant (MDR) substrate. To overcome these limitations in this study, a tumor-targeting peptide (CRGDK peptide, a ligand for NRP-1 receptor) conjugate of α-tocopheryl succinate (α-TOS) was synthesized and modified on PTX-loaded lipid aggregate (TL-PTX) to leverage the benefits of α-TOS, which include a) anti-cancer activity, b) increased PTX loading, and c) inhibition of MDR activity. Use of peptide conjugate of α-TOS (α-TOS-CRGDK) in lipid aggregate increased PTX entrapment efficiency by 20%, helped in NRP-1 specific cellular uptake and significantly enhanced apoptotic and cell killing activity (p <0.01) of PTX compared to control formulation (CL-PTX) by inhibiting MDR-activity in melanoma resulting in ∼70% increment in overall survival of melanoma tumor-bearing mice. In conclusion, CRGDK- α-TOS conjugate in association with PTX-loaded liposome provided a unique NRP-1 targeted, drug-resistant reversing anticancer regimen for treating aggressive melanoma.

Hsa_circ_0000098 is a novel therapeutic target that promotes hepatocellular carcinoma development and resistance to doxorubicin

Background

Circular RNA (circRNA) is crucial to the progression of hepatocellular cancer (HCC). In addition, Mitochondrial calcium uniporter regulatory factor 1 (MCUR1) is commonly overexpressed in HCC to increase cellular ATP levels. Due to the highly aggressive characteristics of HCC, it is essential to identify new diagnostic biomarkers and therapeutic targets that may facilitate the diagnosis of HCC and the development of effective anti-HCC treatments.

Methods

A series of in vitro and in vivo experiments were undertaken to investigate the biological importance and underlying mechanisms of circ_0000098 in HCC.

Results

The expression of circ_0000098 was higher in HCC tissues compared to paired adjacent tissues. According to the receiver-operating characteristic curves, circ_0000098 functioned as a potential diagnostic tumor marker in HCC. Our experiments indicated that circ_0000098 served as a key oncogenic circRNA to increase HCC cell proliferation and invasion in vitro and HCC progression in vivo. Furthermore, mechanistic investigation demonstrated that by sequestering miR-383 from the 3′-UTR of MCUR1, circ_0000098 positively regulated MCUR1 expression in HCC cells and finally promoted HCC progression. On the other hand, inhibiting circ_0000098 in HCC cells could diminish doxorubicin (DOX) resistance by decreasing P-glycoprotein (P-gp, MDR1) expression and intracellular ATP levels. Either downregulation of MCUR1 or overexpression of miR-383 improved DOX sensitivity in HCC cells. Subsequently, a short hairpin RNA targeting circ_0000098 (referred to as sh-1) and doxorubicin (DOX) were encapsulated into platelets (PLTs), referred to as DOX/sh-1@PLT. Activated DOX/sh-1@PLT through HCC cells resulted in the creation of platelet-derived particles that were capable of delivering the DOX/sh-1 combination into HCC cells and promoting intracellular DOX accumulation. Furthermore, our in vivo experiments showed that DOX/sh-1@PLT can effectively reduce P-gp expression, promote DOX accumulation, and reverse DOX resistance.

Conclusions

Our results demonstrated that circ_0000098 is an oncogenic circRNA that promotes HCC development through the miR-383/MCUR1 axis and targeting circ_0000098 with DOX/sh-1@PLT may be a promising and practical therapeutic strategy for preventing DOX resistance in HCC.

Nucleic acid strategies for infectious disease treatments: The nanoparticle-based oral delivery route

Therapies based on orally administrated nucleic acids have significant potential for the treatment of infectious diseases, including chronic inflammatory diseases such as inflammatory bowel disease (IBD)-associated with the gastrointestinal (GI) tract, and infectious and acute contagious diseases like coronavirus disease 2019 (COVID-19). This is because nucleic acids could precisely regulate susceptibility genes in regulating the pro- and anti-inflammatory cytokines expression related to the infections. Unfortunately, gene delivery remains a major hurdle due to multiple intracellular and extracellular barriers. This review thoroughly discusses the challenges of nanoparticle-based nucleic acid gene deliveries and strategies for overcoming delivery barriers to the inflammatory sites. Oral nucleic acid delivery case studies were also present as vital examples of applications in infectious diseases such as IBD and COVID-19.

Asparagus officinalis combined with paclitaxel exhibited synergistic anti-tumor activity in paclitaxel-sensitive and -resistant ovarian cancer cells

PURPOSE

Although paclitaxel is a promising first-line chemotherapeutic drug for ovarian cancer, acquired resistance to paclitaxel is one of the leading causes of treatment failure, limiting its clinical application. Asparagus officinalis has been shown to have anti-tumorigenic effects on cell growth, apoptosis, cellular stress and invasion of various types of cancer cells and has also been shown to synergize with paclitaxel to inhibit cell proliferation in ovarian cancer.

METHODS

Human ovarian cancer cell lines MES and its PTX-resistant counterpart MES-TP cell lines were used and were treated with Asparagus officinalis and paclitaxel alone as well as in combination. Cell proliferation, cellular stress, invasion and DMA damage were investigated and the synergistic effect of a combined therapy analyzed.

RESULTS

In this study, we found that Asparagus officinalis combined with low-dose paclitaxel synergistically inhibited cell proliferation, induced cellular stress and apoptosis and reduced cell invasion in paclitaxel-sensitive and -resistant ovarian cancer cell lines. The combined treatment effects were dependent on DNA damage pathways and suppressing microtubule dynamics, and the AKT/mTOR pathway and microtubule-associated proteins regulated the inhibitory effect through different mechanisms in paclitaxel-sensitive and -resistant cells.

CONCLUSION

These findings suggest that the combination of Asparagus officinalis and paclitaxel have potential clinical implications for development as a novel ovarian cancer treatment strategy.

γ-Glutamylcysteine Exerts Neuroprotection Effects against Cerebral Ischemia/Reperfusion Injury through Inhibiting Lipid Peroxidation and Ferroptosis

Ferroptosis is a non-apoptotic form of cell death driven by iron-dependent lipid peroxidation. Recent evidence indicates that inhibiting ferroptosis could alleviate cerebral ischemia/reperfusion (CIR) injury. γ-glutamylcysteine (γ-GC), an intermediate of glutathione (GSH) synthesis, can upregulate GSH in brains. GSH is the co-factor of glutathione peroxidase 4 (GPX4), which is the negative regulator of ferroptosis. In this study, we explored the effect of γ-GC on CIR-induced neuronal ferroptosis and brain injury. We found that γ-GC significantly reduced the volume of cerebral infarction, decreased the loss of neurons and alleviated neurological dysfunction induced by CIR in rats. Further observation showed that γ-GC inhibited the CIR-caused rupture of the neuronal mitochondrial outer membrane and the disappearance of cristae, and decreased Fe2+ deposition and lipid peroxidation in rat cerebral cortices. Meanwhile, γ-GC altered the expression of some ferroptosis-related proteins in rat brains. Mechanistically, γ-GC increased the expression of GSH synthetase (GSS) for GSH synthesis via protein kinase C (PKC)ε-mediated activation of nuclear factor erythroid 2-related factor (Nrf2). Our findings suggest that γ-GC not only serves as a raw material but also increases the GSS expression for GSH synthesis against CIR-induced lipid peroxidation and ferroptosis. Our study strongly suggests that γ-GC has potential for treating CIR injury.

Generation of Two Paclitaxel-Resistant High-Grade Serous Carcinoma Cell Lines With Increased Expression of P-Glycoprotein

Debulking surgery followed by chemotherapy are the standard of care for high-grade serous carcinoma. After an initial good response to treatment, the majority of patients relapse with a chemoresistant profile, leading to a poor overall survival. Chemotherapy regimens used in high-grade serous carcinomas are based in a combination of classical chemotherapeutic drugs, namely, Carboplatin and Paclitaxel. The mechanisms underlying drug resistance and new drug discovery are crucial to improve patients’ survival. To uncover the molecular mechanisms of chemoresistance and test drugs capable of overcoming this resistant profile, it is fundamental to use good cellular models capable of mimicking the chemoresistant disease. Herein, we established two high-grade serous carcinoma cell lines with intrinsic resistance to Carboplatin and induced Paclitaxel resistance (OVCAR8 PTX R C and OVCAR8 PTX R P) derived from the OVCAR8 cell line. These two chemoresistant cell line variants acquired an enhanced resistance to Paclitaxel-induced cell death by increasing the drug efflux capacity, and this resistance was stable in long-term culture and following freeze/thaw cycles. The mechanism underlying Paclitaxel resistance resides in a significant increase in P-glycoprotein expression and, when this drug efflux pump was blocked with Verapamil, cells re-acquired Paclitaxel sensitivity. We generated two high-grade serous carcinoma cell lines, with a double-chemoresistant (Carboplatin and Paclitaxel) phenotype that mimics the majority of tumor recurrences in ovarian cancer context. This robust tool is suitable for preliminary drug testing towards the development of therapeutic strategies to overcome chemoresistance.

Redox-sensitive carrier-free nanoparticles self-assembled by disulfide-linked paclitaxel-tetramethylpyrazine conjugate for combination cancer chemotherapy

Rationale: Combinations of two or more therapeutic agents targeting different signaling pathways involved in tumor progression can have synergistic anticancer effects. However, combination chemotherapies are greatly limited by the different pharmacokinetics, tumor targeting, and cellular uptake capacities of the combined drugs. We have previously demonstrated the potential synergistic efficacy of paclitaxel (PTX) and the natural anti-angiogenic agent tetramethylpyrazine (TMP) for suppressing ovarian carcinoma growth. An efficient, facile, and smart nanosystem to deliver PTX and TMP simultaneously in vivo is greatly desired.

Methods: We constructed a redox-sensitive nanosystem based on the amphiphilic PTX-ss-TMP conjugate, in which PTX and TMP are linked by a disulfide bond. We characterized the structure of the drug conjugate by ¹H NMR and LC-MS, and then prepared PTX-ss-TMP NPs by a one-step nanoprecipitation method. We investigated the redox sensitivity, tumor-targeting ability, anticancer efficacy, and anti-angiogenesis activity of PTX-ss-TMP NPs in vitro and in vivo.

Results: The amphiphilic PTX-ss-TMP conjugate readily self-assembled into stable nanoparticles in aqueous solution with a low critical association concentration of 1.35 µg/mL, well-defined spherical structure, small particle size (152 nm), high drug loading, redox-responsive drug release, high biocompatibility, and high storage stability. In cancer cells pretreated with GSH-OEt, PTX-ss-TMP NPs exhibited higher cytotoxicity, apoptosis rate, and cell-cycle arrest than monotherapy or combination therapy with free drugs, which was attributed to their improved cellular uptake and rapid intracellular drug release. Additionally, PTX-ss-TMP NPs also had a stronger anti-angiogenesis effect in HUVECs than free drug, which was mediated by VEGFR2-involved downstream signals. Finally, PTX-ss-TMP NPs showed tumor-specific accumulation and excellent antitumor activity in A2780 xenograft mice compared with free drug.

Conclusions: These in vitro and in vivo results provide clear evidence that this redox-responsive carrier-free nanosystem with intrinsic amphiphilicity has great potential for combination cancer chemotherapy.

Esomeprazole overcomes paclitaxel-resistance and enhances anticancer effects of paclitaxel by inducing autophagy in A549/Taxol cells

Non-small-cell lung cancer (NSCLC) is one of the most common malignancies, and the occurrence of drug-resistance severely limits the efficacy of anticancer drugs in the treatment of NSCLC. Identification of new agents to reverse drug-resistance in NSCLC treatment is of great importance and urgency both clinically and scientifically. In the present study, we found that A549/Taxol cells displayed a high level of resistance to paclitaxel with the resistance index up to 231. Importantly, esomeprazole could potentiate the antiproliferative effect of paclitaxel in A549/Taxol cells, but not in A549 cells. Further exploration on the underlying mechanisms revealed that esomeprazole decreased the intracellular pH via inhibiting V-ATPase expression in A549/Taxol cells. Meanwhile, esomeprazole pretreatment significantly promoted paclitaxel-induced polymerization of tubulin and enhanced the proportion of G2/M-arrested cells in A549/Taxol cells. Unfortunately, esomeprazole could only result in a slight decrease in the expression of P-gp in A549/Taxol cells. Interestingly, esomeprazole significantly increased paclitaxel-induced apoptosis, which was impeded by the autophagy inhibitor 3-MA in A549/Taxol cells. Taken together, our data suggest that esomeprazole is a promising chemosensitizer against paclitaxel-resistant NSCLC by inducing autophagy. Our study also offers a new strategy to solve the paclitaxel-resistance problem during NSCLC treatment.

Predicting and Overcoming Taxane Chemoresistance

Taxanes are microtubule-targeting drugs used as cytotoxic chemotherapy to treat most solid tumors. The development of resistance to taxanes is a major cause of therapeutic failure and overcoming chemoresistance remains an important challenge to improve patient's outcome. Extensive efforts have been made recently to identify predictive biomarkers to select populations of patients who will benefit from taxane-based chemotherapy and avoid inefficient treatment of patients with innate resistance. This, together with the discovery of new mechanisms of resistance that include metabolic reprogramming and dialogue between tumor and its microenvironment, pave the way to a new era of personalized medicine. In this review, we recapitulate recent insights into taxane resistance and present promising emerging strategies to overcome chemoresistance in the future.

Nanoparticle Drug Delivery System for Glioma and Its Efficacy Improvement Strategies: A Comprehensive Review

Gliomas are the most common tumor of the central nervous system. However, the presence of the brain barrier blocks the effective delivery of drugs and leads to the treatment failure of various drugs. The development of a nanoparticle drug delivery system (NDDS) can solve this problem. In this review, we summarized the brain barrier (including blood-brain barrier (BBB), blood-brain tumor barriers (BBTB), brain-cerebrospinal fluid barrier (BCB), and nose-to-brain barrier), NDDS of glioma (such as passive targeting systems, active targeting systems, and environmental responsive targeting systems), and NDDS efficacy improvement strategies and deficiencies. The research prospect of drug-targeted delivery systems for glioma is also discussed.

Strategies for nonviral nanoparticle-based delivery of CRISPR/Cas9 therapeutics

CRISPR-based genome editing technology has become an important potential therapeutic tool for various diseases. A vital challenge is to reach a safe, efficient, and clinically suitable delivery of a CRISPR-associated protein and a single-guide RNA. A possible translational approach to applying CRISPR-based technology is the use of viral vectors such as adeno-associated virus. However, such vectors give long-term exposure in vivo that may increase potential off-target effects as well as the risk of immunogenicity. Therefore, limitations to clinical applications are addressed using nonviral delivery systems such as nanoparticle-based delivery strategies. Today, the nanoparticle-based delivery approach is becoming more and more attractive in gene therapeutics because of its specific targeting, scale-up efficiency, efficacy of customization, minor stimulation of immune response, and minimal exposure to nucleases. In this review, we will present the most recent advances in developing innovations and potential advantages of the nanoparticle delivery system in CRISPR genome editing. We will also propose potential strategies of CRISPR-based technology for therapeutic and industrial applications. Our review will differ in focus from previous reviews and advance the literature on the subject by (a) focusing on the challenges of the CRISPR/Cas9 delivery system; (b) focusing on the application of nanoparticle-based delivery of CRISPR components (Cas9 and sgRNA), such as lipids and polymeric vectors; (c) discussing the potential nanoparticle-based delivery approaches for CRISPR/Cas9 application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Treatment of Metastatic or High-Risk Solid Cancer Patients by Targeting the Immune System and/or Tumor Burden: Six Cases Reports

This article summarizes the histories of six patients with different solid tumors treated with a new strategy based on tumor burden reduction and immune evasion as potential targets. All six patients were at a high risk of relapse and were likely to have a minimal residual disease following conventional therapy: biochemical recurrence (BCR) following radical prostatectomy (RP) (two prostate cancers patients), removal of distant metastases (one colorectal and one breast cancer), and complete response (CR) of distant metastases to conventional therapy (one breast cancer and one esophageal–gastric junction cancer). Four of the patients, two after RP and BCR, one after removal of a single pulmonary metastasis from breast cancer, and one after CR to chemotherapy of peritoneal metastases and ascites from an esophageal–gastric junction primary cancer, regularly received cycles of a new drug schedule with the aim of inhibiting immune suppression (IT). In these four patients, preliminary laboratory tests of peripheral blood suggested an interleukin (IL)-2/IL-12 mediated stimulation of cellular immune response with a concomitant decrease in vascular endothelial growth factor (VEGF) immune suppression. The fifth case was a breast cancer patient with distant metastases in CR, while receiving beta-interferon and interleukin-2 in addition to conventional hormone therapy. To date, all five patients are alive and doing well and they have been unexpectedly disease-free for 201 and 78 months following BCR, 28 months following the removal of a single pulmonary metastases, 32 months following CR to chemotherapy of peritoneal metastases and ascites, and 140 months following diagnosis of multiple bone metastases, respectively. The sixth patient, who had colorectal cancer and multiple synchronous liver metastases and underwent nine surgical interventions for metastatic disease, although not disease-free, is doing well 98 months after primary surgery. Our six cases reports can be interpreted with the hypothesis that immune manipulation and/or a concomitant low tumor burden favored their clinical outcome.

Targeting Mutant KRAS for Anticancer Therapy

:

Over the past decades, designing therapeutic strategies to target KRAS-mutant cancers, which is one of the most frequent mutant oncogenes among all cancer types, have proven unsuccessful regardless of many concerted attempts. There are key challenges for KRAS-mutant anticancer therapy, as the complex cellular processes involved in KRAS signaling has present. Herein, we highlight the emerging therapeutic approaches for inhibiting KRAS signaling and blocking KRAS functions, in hope to serve as a more effective guideline for future development of therapeutics.

Expression levels of MRP1, GST-π, and GSK3β in ovarian cancer and the relationship with drug resistance and prognosis of patients

Expression levels of multidrug resistance-associated protein 1 (MRP1), glutathione S-transferase π (GST-π) and glycogen synthase kinase-3β (GSK3β) were investigated in ovarian epithelial cancer and the relationship with the primary drug resistance of patients with ovarian cancer to chemotherapy. One hundred and twenty-one ovarian cancer tissue samples from patients who underwent ovarian cancer resection from January 2013 to June 2015 in Liaoning Cancer Hospital and Institute, Cancer Hospital of China Medical University were enrolled in the Experimental group, while 58 ovarian tissue samples from patients with fallopian tube obstruction but with no ovarian cancer who received surgical treatment for blocked fallopian tube were included in the Control group. After the detection of the expression levels of MRP1, GST-π, and GSK3β mRNA by RT-PCR and the analysis of related clinical pathological factors, patients in the Experimental group were divided into the Chemotherapy-sensitive and Chemotherapy-resistant groups according to the chemotherapy efficacy. Additionally, with the mean expression levels of MRP1, GST-π, and GSK3β in ovarian cancer tissues as the boundaries, the expression levels of the three genes in the Experimental group were classified into high expression and low expression. Ovarian cancer tissues had much higher expression levels of MRP1, GST-π, and GSK3β mRNA than normal ovarian tissues (P<0.05). The expression levels of MRP1, GST-π, and GSK3β mRNA in the Chemotherapy-sensitive group were significantly lower than those in the Chemotherapy-resistant group (P<0.05). Patients with high expression of MRP1, GST-π, and GSK3β mRNA had a much lower 3-year survival rate than patients with low expression of the genes (P<0.05). Highly expressed in patients with ovarian cancer, MRP1, GST-π, and GSK3β mRNA play an important role in the development and drug resistance of ovarian cancer, which ensures this study is of positive clinical guiding significance in developing proper treatment for ovarian cancer and evaluating the efficacy of chemotherapy.

Redox-responsive nano-carriers as tumor-targeted drug delivery systems

With ever increasing scientific knowledge and awareness, research is underway around the globe to design new types of stimuli (external/internal) responsive nano-carriers for biotechnological applications at large and biomedical/pharmaceutical in particular. Based on literature evidence, stimuli-responsive carriers have been classified into four major categories, i.e. (1) physical, (2) chemical, (3) biological, and (4) dual (combination of any of the first three classes). Among various types, redox-responsive nano-carriers are of supreme interests and discussed here in this review. The difference in redox potential in tumor and normal tissue is considered as a potential target for tumor targeting leading to the development of redox-responsive drug delivery systems (DDS). In this regard, a high concentration of glutathione in tumor/intracellular environment has extensively been exploited. Disulfide bonds were found as a promising tool for designing redox-responsive which tend to cleave in a reductive environment forming sulfhydryl groups. Many nano-carriers have been explored widely to control tumor growth. These systems were used against the tumor xenograft animal model and showed improved tumor targeting with tumor growth inhibition. Herein, an effort has been made to summarize various aspects from design to development of numerous types of redox-responsive DDS including liposomes, micelles, nanoparticles, nanogel and prodrug based nanomedicines. An emphasis is also given on various types of nano-carriers with special reference to the tumor-targeted drug delivery applications. Also, dual responsive nano-carriers (in addition to redox-responsive) have also been briefly discussed. Towards the end of the chapter, the information is also given on their future perspectives.

Nanocarrier-Mediated Chemo-Immunotherapy Arrested Cancer Progression and Induced Tumor Dormancy in Desmoplastic Melanoma

In desmoplastic melanoma, tumor cells and tumor-associated fibroblasts are the major dominators playing a critical role in the fibrosis morphology as well as the immunosuppressive tumor microenvironment (TME), compromising the efficacy of therapeutic options. To overcome this therapeutic hurdle, we developed an innovative chemo-immunostrategy based on targeted delivery of mitoxantrone (MIT) and celastrol (CEL), two potent medicines screened and selected with the best anticancer and antifibrosis potentials. Importantly, CEL worked in synergy with MIT to induce immunogenic tumor cell death. Here, we show that when effectively co-delivered to the tumor site at their optimal ratio by a TME-responsive nanocarrier, the 5:1 combination of MIT and CEL significantly triggered immunogenic tumor apoptosis and recovered tumor antigen recognition, thus eliciting overall antitumor immunity. Furthermore, the strong synergy benefitted the host in reduced drug exposure and side effects. Collectively, the nanocarrier-mediated chemo-immunotherapy successfully remodeled fibrotic and immunosuppressive TME, arrested cancer progression, and further inhibited tumor metastasis to major organs. The affected tumors remained dormant long after dosing stopped, resulting in a prolonged progression-free survival and sustained immune surveillance of the host bearing desmoplastic melanoma.