Denosumab: a new option in the treatment of bone metastases from urological cancers

Cell Membrane-Camouflaged Chitosan-Polypyrrole Nanogels Co-Deliver Drug and Gene for Targeted Chemotherapy and Bone Metastasis Inhibition of Prostate Cancer

The development of functional nanoplatforms to improve the chemotherapy outcome and inhibit distal cancer cell metastasis remains an extreme challenge in cancer management. In this work, a human-derived PC-3 cancer cell membrane-camouflaged chitosan-polypyrrole nanogel (CH-PPy NG) platform, which can be loaded with chemotherapeutic drug docetaxel (DTX) and RANK siRNA for targeted chemotherapy and gene silencing-mediated metastasis inhibition of late-stage prostate cancer in a mouse model, is reported. The prepared NGs with a size of 155.8 nm show good biocompatibility, pH-responsive drug release profile, and homologous targeting specificity to cancer cells, allowing for efficient and precise drug/gene co-delivery. Through in-vivo antitumor treatment in a xenografted PC-3 mouse tumor model, it is shown that such a CH-PPy NG-facilitated co-delivery system allows for effective chemotherapy to slow down the tumor growth rate, and effectively inhibits the metastasis of prostate cancer to the bone via downregulation of the RANK/RANKL signaling pathway. The created CH-Ppy NGs may be utilized as a promising platform for enhanced chemotherapy and anti-metastasis treatment of prostate cancer.

Nanoparticle-mediated synergistic drug combination for treating bone metastasis

Bone metastasis at an advanced disease stage is common in most solid tumors and is untreatable. Overexpression of receptor activator of nuclear factor κB ligand (RANKL) in tumor-bone marrow microenvironment drives a vicious cycle of tumor progression and bone resorption. Biodegradable nanoparticles (NPs), designed to localize in the tumor tissue in bone marrow, were evaluated in a prostate cancer model of bone metastasis. The combination treatment, encapsulating docetaxel, an anticancer drug (TXT-NPs), and Denosumab, a monoclonal antibody that binds to RANKL (DNmb-NPs), administered intravenously regressed the tumor completely, preventing bone resorption, without causing any mortality. With TXT-NPs alone treatment, after an initial regression, the tumor relapsed and acquired resistance, whereas DNmb-NPs alone treatment was ineffective. Only in the combination treatment, RANKL was not detected in the tumor tibia, thus negating its role in tumor progression and bone resorption. The combination treatment was determined to be safe as the vital organ tissue showed no increase in inflammatory cytokine or the liver ALT/AST levels, and animals gained weight. Overall, dual drug treatment acted synergistically to modulate the tumor-bone microenvironment with encapsulation enhancing their therapeutic potency to achieve tumor regression.

Pleural empyema due to Salmonella in a patient with bronchogenic carcinoma: the first case report from a cancer hospital in Egypt

Background

Salmonella species are motile, Gram-negative facultative anaerobic bacilli, which belong to the family Enterobacteriaceae. The most common clinical presentations of Salmonella infection are gastroenteritis and enteric fever. Detection of Salmonella organisms in empyema is very rare.

Case presentation

We report the case of a 66-year-old female patient with bronchogenic carcinoma who developed empyema, and Salmonella was identified from the culture of pleural fluid. After antimicrobial therapy and other therapeutic measures, including the insertion of an intercostal tube, oxygen supplementation, frequent suction of respiratory secretions, and chest physiotherapy, the patient's condition improved. To the best of our knowledge, this is the first case to be reported in Egypt.

Conclusions

Our case sheds light on the role of Salmonella in immunocompromised patients in general and cancer patients in specific. We recommend further study of this role, since it may lead to a better understanding of the pathogenicity of this organism in these patients.

Synergistic combination treatment to break cross talk between cancer cells and bone cells to inhibit progression of bone metastasis

Advanced-stage cancers often metastasize to bone, and is the major cause of cancer-related morbidity and mortality. Due to poor biodistribution of intravenously administered anticancer drugs within the bone, chemotherapy is not optimally effective in treating bone metastasis. Additionally, overexpression of receptor activator of nuclear factor κB ligand (RANKL) in the bone microenvironment drives the vicious, destructive cycle of progression of bone metastasis and bone resorption. We hypothesized that the combination treatment - with docetaxel (TXT), an anticancer drug encapsulated in sustained release biodegradable nanoparticles (TXT-NPs) that are designed to localize in bone marrow, and denosumab monoclonal antibody (DNmb), which binds to RANKL - could be more effective than either treatment alone. We tested our hypothesis in intraosseous prostate cancer (PC-3) cell-induced osteolytic mouse model of bone metastasis with treatments given intravenously. The results demonstrated better efficacy with TXT-NPs than with TXT-CrEL or saline control in inhibiting progression of metastasis and improving survival. TXT-NPs showed ~3-fold higher drug levels in metastasized bone tissue at 1 wk post-administration than TXT-CrEL, thus explaining their efficacy. However, the combination treatment (TXT-NPs + DNmb) given simultaneously was significantly more effective in inhibiting metastatic progression; it caused early tumor regression and improved survival, and caused no body weight loss or tumor relapse, even when the treatment was discontinued, whereas TXT-NPs or DNmb alone treatments showed tumor relapse after an initial regression. Micro-CT analysis of the bone from the combination treatment showed no bone loss and normal bone mineral content, bone density, and bone volume fraction, whereas TXT-NPs or DNmb alone treatments showed bone loss. Confirming the above results, histochemical analysis of the bone from the combination treatment demonstrated normal bone morphology, and osteoblast and osteoclast cell activities. In conclusion, TXT-NPs and DNmb in combination, because of their complementary roles in breaking the cross talk between cancer cells and bone cells, was significantly effective in treating bone metastasis.

The antinociceptive effect of resveratrol in bone cancer pain is inhibited by the Silent Information Regulator 1 inhibitor selisistat

Objectives

To study the antinociceptive effect of single and repeated doses of resveratrol in a bone cancer pain model, and whether this effect is prevented by the Silent Information Regulator 1 (SIRT1) inhibitor selisistat.

Methods

The femoral intercondylar bone of BALB/c mice was injected with 1 000 000 BJ3Z cancer cells. Bone resorption and tumour mass growth (measured by in vivo X-ray and fluorescence imaging), as well as mechanical nociceptive thresholds (von Frey device) and dynamic functionality (rotarod machine), were evaluated during the following 4 weeks. Acute resveratrol (100 mg/kg i.p.) and/or selisistat (10 mg/kg s.c.) were administered on day 14. Chronic resveratrol (100 mg/kg i.p., daily) and/or selisistat (0.5 μg/h s.c., Alzet pump) were administered between days 14 and 20.

Key findings

Tumour growth gradually incremented until day 31, while mechanical hyperalgesia started on day 3 after cancer cell injection. Acute resveratrol increased the mechanical threshold of pain (peaking at 1.5 h), while the dynamic functionality decreased. Chronic resveratrol produced a sustained antinociceptive effect on mechanical hyperalgesia and improved the loss of dynamic functionality induced by the bone cancer tumour. Selisistat prevented all the effects of resveratrol.

Conclusions

Acute and chronic resveratrol induces antinociceptive effect in the model of metastatic osseous oncological pain, an effect that would be mediated by SIRT1 molecular signalling.

Severe Hypophosphatemia Following Denosumab Administration in a Hemodialysis Patient with Progressive Prostate Cancer

In a 68-year-old man on maintenance hemodialysis (HD), severe anemia was detected. Bone marrow biopsy was performed for investigation of pancytopenia and pathological examination revealed adenocarcinoma of the prostate. Prostate specific antigen (PSA) was 574 ng/mL. After androgen deprivation therapy was initiated, PSA decreased to 13.7 ng/mL. But subsequent elevation of PSA and pain due to bone metastases were recognized. Denosumab (120 mg) was administered. Although improvement of bone pain was observed, severe hypocalcemia occurred. Severe hypophosphatemia was subsequently detected. When we use denosumab in dialysis patients with advanced cancer, we should be careful of hypophosphatemia.

Improvement of renal function by changing the bone-modifying agent from zoledronic acid to denosumab

Background

In order to help in selecting the optimum bone-modifying agent (BMA; zoledronic acid or denosumab), we investigated the impact of the BMA on the renal function of patients with bone metastases.

Materials and methods

The present study consisted of 118 patients who were treated with denosumab for bone metastases secondary to prostate cancer, renal cell cancer, and urothelial cancer at our hospital between 2012 and 2015. The clinical course of the renal function of these patients, treated with zoledronic acid or denosumab, was retrospectively evaluated.

Results

Of the 118 patients who were treated with denosumab during the study period, 57 (48 %) had previously been administered zoledronic acid and 61 (52 %) had received denosumab as the first-line BMA. The reasons for changing from zoledronic acid to denosumab were increased creatinine serum level (26 patients, 46 %), patient preference (16 patients, 28 %), difficulty with venous infusion (10 patients, 17 %), and other reasons (5 patients, 9 %). The median level of creatinine clearance in the patients who changed from zoledronic acid to denosumab due to increased serum creatinine level was 59.9 ml/min before administration of zoledronic acid, 40.9 ml/min at the beginning of denosumab treatment, 47.5 ml/min at 3 months after administration of denosumab, and 52.0 ml/min at the last follow-up. There were significant differences.

Conclusions

For the first time, we demonstrated that the renal function of some patients, which had deteriorated following zoledronic acid administration, successfully improved after changing to denosumab.

Denosumab: A bone antiresorptive drug

Bone remodeling is the continuous process by which old bone is removed by bone-resorbing cells, the osteoclasts and replaced by new bone synthesized by bone forming cells, the osteoblasts. Osteoporosis is characterized by a progressive loss of bone mass and microarchitecture, which leads to increased fracture risk. Denosumab, a human monoclonal antibody resembling natural IgG2 immunoglobulin, has antiresorptive activity and is distinguished from other antiresorptive drugs. It mimics osteoprotegerin (OPG) that binds to RANKL and hence does not allow RANKL to bind with RANK receptor, thereby inhibiting osteoclast differentiation, activation and survival exerting primarily antiresorptive action. Denosumab trials have shown its efficacy in postmenopausal women with osteoporosis, unresectable giant cell tumor of bone and significant effect in non-metastatic prostate cancer and delay in the time-to-first skeletal related events (SRE) and subsequent SRE with denosumab than zoledronic acid in patients. It is available as 60 mg/ml in pre-filled syringes and approved for osteoporosis in postmenopausal women (60 mg s.c. twice yearly), unresectable giant cell tumor of bone in adults and skeletally mature adolescents (120 mh s.c. monthly), prevention of skeletal-related events and to increase bone mass in patients at high risk for fracture including androgen deprivation therapy for non-metastatic prostate cancer or adjuvant aromatase inhibitor therapy for breast cancer. Denosumab offers advantages of twice yearly dosing in osteoporosis and monthly dosing in giant cell tumor of bone with its novel mechanism of action and better tolerability.

XPO1/CRM1-selective inhibitors of nuclear export (SINE) reduce tumor spreading and improve overall survival in preclinical models of prostate cancer (PCa)

BACKGROUND

Exportin 1 (XPO1), also called chromosome region maintenance 1 (CRM1), is the sole exportin mediating transport of many multiple tumor suppressor proteins out of the nucleus.

AIM AND METHODS

To verify the hypothesis that XPO1 inhibition affects prostate cancer (PCa) metastatic potential, orally available, potent and selective, SINE compounds, Selinexor (KPT- 330) and KPT-251, were tested in preclinical models known to generate bone lesions and systemic tumor spread.

RESULTS

In vitro, Selinexor reduced both secretion of proteases and ability to migrate and invade of PCa cells. SINEs impaired secretion of pro-angiogenic and pro-osteolytic cytokines and reduced osteoclastogenesis in RAW264.7 cells. In the intra-prostatic growth model, Selinexor reduced DU145 tumor growth by 41% and 61% at the doses of 4 mg/Kg qd/5 days and 10 mg/Kg q2dx3 weeks, respectively, as well as the incidence of macroscopic visceral metastases. In a systemic metastasis model, following intracardiac injection of PCb2 cells, 80% (8/10) of controls, 10% (1/10) Selinexor- and 20% (2/10) KPT-251-treated animals developed radiographic evidence of lytic bone lesions. Similarly, after intra-tibial injection, the lytic areas were higher in controls than in Selinexor and KPT-251 groups. Analogously, the serum levels of osteoclast markers (mTRAP and type I collagen fragment, CTX), were significantly higher in controls than in Selinexor- and KPT-251-treated animals. Importantly, overall survival and disease-free survival were significantly higher in Selinexor- and KPT-251-treated animals when compared to controls.

CONCLUSIONS

Selective blockade of XPO1-dependent nuclear export represents a completely novel approach for the treatment of advanced and metastatic PCa.

Prolonged hypocalcemia following denosumab therapy in metastatic hormone refractory prostate cancer

Prostate cancer is a leading cause of cancer death, frequently associated with widespread bone metastases. We report two cases of hypocalcemia following the first dose of denosumab in metastatic hormone refractory prostate cancer, the first case requiring 26 days of intravenous calcium therapy. This is the first report of prolonged hypocalcemia following denosumab in a patient with normal renal function.

Combinational usage of next generation sequencing and qPCR for the analysis of tumor samples

The combination of multiple techniques especially those adding complementary information have proven to be beneficial in terms of data consistency. The employment of quantitative PCR (qPCR) prior to next generation sequencing (NGS) methods such as RNA-Seq and mutational analysis presented here does not only enhance data in terms of CNV integration and sample choice, but also allows a faster and more efficient workflow. Correct analysis of libraries prior to sequencing has proven to be a vital step for specific assumption and to some extent for a more parallel testing. By illustrating the combination of qPCR and NGS in oncological examples, the potential of this approach is presented.