The combination of everolimus and zoledronic acid increase the efficacy of gemcitabine in a mouse model of pancreatic adenocarcinoma

Effects of percutaneous kyphoplasty combined with zoledronic acid injection on osteoporotic vertebral compression fracture and bone metabolism indices

BACKGROUND

Osteoporotic vertebral compression fracture (OVCF) is usually treated by percutaneous kyphoplasty (PKP) which has limitations. We aimed to evaluate the effects of PKP combined with zoledronic acid (ZOL) injection on OVCF and bone metabolism indices.

METHODS

A total of 600 OVCF patients admitted from June 2015 to June 2020 were randomly divided into group A (PKP alone), group B (PKP combined with ZOL 1 month later) and group C (PKP concurrently combined with ZOL) (N.=200). Before as well as 1 month (before ZOL treatment in group B) and 1 year after PKP, the pain degree, physical function and self-care ability in daily life were assessed, the height and kyphosis Cobb angle of vertebral body with compression fracture and bone mineral densities (BMDs) at different parts were measured, the clinical efficacy, adverse reactions and recurrence of vertebral fractures during 3 years of follow-up were observed, and the serum levels of BAP, BGP, β-CTx and TP1NP were detected.

RESULTS

Compared with groups A and B, group C had significantly reduced visual analogue scale (VAS) and Oswestry disability index (ODI) scores and raised activity of daily living (ADL) score 1 month after PKP (P<0.05). Groups A-C had successively lowered VAS and ODI scores and elevated ADL Score 1 year after PKP (P<0.05). Compared with before PKP, the height of vertebral body with compression fracture significantly increased, and the kyphosis Cobb angle decreased in the three groups 1 month and 1 year after PKP (P<0.05). In group A, the height was lower whereas the angle was larger 1 year after PKP than those 1 month after PKP (P<0.05). One month after PKP, the height was significantly higher and the angle was smaller in group C than those of groups A and B (P<0.05). One year after PKP, the height significantly increased and the angle decreased successively in groups A-C (P<0.05). BMDs at different parts were significantly higher in group C than those of groups A and B 1 month after PKP (P<0.05). One year after PKP, BMDs were highest in group C and lowest in group A (P<0.05). The overall response rate was significantly higher in group C than that in group A (P<0.05). The recurrence rate of fractures was significantly higher in group A than those of groups B and C (P<0.05). The BAP, BGP, β-CTx and TP1NP levels were significantly lower in group C than those of groups A and B 1 month after PKP (P<0.05), and declined successively in groups A-C 1 year after PKP (P<0.05).

CONCLUSIONS

PKP concurrently combined with ZOL exert the most significant therapeutic effects on OVCF, with the lowest recurrence rate of fractures. It relieves pain and improves the physical function and self-care ability in daily life probably by reducing bone metabolism indices, increasing BMD, and maintaining the height and kyphosis Cobb angle of recovered vertebral body.

Modulated Electro-Hyperthermia Supports the Effect of Gemcitabine Both in Sensitive and Resistant Pancreas Adenocarcinoma Cell Lines

The poor prognosis of pancreatic ductal adenocarcinoma (PDAC) is frequently associated to high treatment resistance. Gemcitabine (GEM) alone or in combination is the most used chemotherapy for unresecable PDACs. Here we studied whether modulated electro-hyperthermia (mEHT), a non-invasive complementary treatment, can support the effect of GEM on PDAC cells in vitro. The LD20 for the GEM-resistant Panc1 cells proved to be 200× higher than for the drug-sensitive Capan1. The mEHT alone caused significant apoptosis in Capan1 cultures as confirmed by the elevated SubG1 phase cell fraction and increased number of cleaved Caspase-3 positive cells 48 h after treatment, with an additive effect when GEM was used after hyperthermia. These were accompanied by reduced number of G1, S, and G2/M phase cells and elevated expression of the cyclin-dependent kinase inhibitor p21waf1 protein. In GEM-resistant Panc1 cells, an initial apoptosis was detected by flow cytometry 24 h after mEHT ± GEM treatment, which however diminished by 48 h at persistent number of cleaved Caspase-3 positive tumor cells. Though GEM monotherapy reduced the number of tumor progenitor colonies in Capan1 cell line, an additive colony inhibitory effect of mEHT was observed after mEHT + GEM treatment. The heat shock induced Hsp27 and Hsp70 proteins, which are known to sensitize PDAC cells to GEM were upregulated in both Capan1 and Panc1 cells 24 h after mEHT treatment. The level of E-Cadherin, a cell adhesion molecule, increased in Capan1 cells after mEHT + GEM treatment. In conclusion, in GEM-sensitive PDAC cells mEHT treatment alone induced cell death and cell cycle inhibition and improved GEM efficiency in combination, which effects were milder and short-term up to 24 h in the GEM-resistant Panc1 cells. Our data further support the inclusion of hyperthermia, in particular of mEHT, into the traditional oncotherapy regimens of PDAC.

Intravesical gemcitabine as bladder‐preserving treatment for BCG unresponsive non‐muscle‐invasive bladder cancer. Results from a single‐arm, open‐label study

Background

There is an unmet alternative medical therapy for BCG unresponsive patients.

Objective

To report efficacy of intravesical gemcitabine in NMIBC patients, who failed a previous course of BCG, or intolerant, and unwilling to undergo radical cystectomy (RC).

Material and methods

This is an open‐label, single‐arm study, which enrolled patients showing a failure or were intolerant to BCG and unwilling to undergo the RC. Intravesical gemcitabine was administered once a week for six consecutive weeks and once a month for 12 months. The primary outcome was DFS defined as the lack of a tumor on cystoscopy and negative urine cytology. Secondary endpoint was safety defined according a grading of side effects. OS, PFS, and DFS were described with Kaplan–Meier method at 12 and 24 months.

Results and limitations

Overall 36 patients were enrolled. The median follow‐up was 27 months. The DFS was 68.75% at the end of induction phase and 44.44% and 31.66% at 12 and 24 months of, respectively. The PFS was 43.75%. The OS and CSS were 77.9% (95% CI 58.78%‐88.92%) and 80.68% (95% CI 61.49%‐90.96%), respectively. There was no life threatening event or treatment‐related death (grade 4 or 5). The most common mild and moderate adverse events reported were urinary symptoms (LUTS) and fatigue (G1‐G2).

Conclusion

Patients who presented an unresponsive‐BCG recurrent NMIBC and unwilling to receive a RC, could benefit from intravesical gemcitabine as salvage organ‐sparing treatment.

Hypoxia as a barrier to immunotherapy in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease with limited response to cytotoxic chemoradiotherapy, as well as newer immunotherapies. The PDA tumor microenvironment contains infiltrating immune cells including cytotoxic T cells; however, there is an overall immunosuppressive milieu. Hypoxia is a known element of the solid tumor microenvironment and may promote tumor survival. Through various mechanisms including, but not limited to, those mediated by HIF-1α, hypoxia also leads to increased tumor proliferation and metabolic changes. Furthermore, epithelial to mesenchymal transition is promoted through several pathways, including NOTCH and c-MET, regulated by hypoxia. Hypoxia-promoted changes also contribute to the immunosuppressive phenotype seen in many different cell types within the microenvironment and thereby may inhibit an effective immune system response to PDA. Pancreatic stellate cells (PSCs) and myofibroblasts appear to contribute to the recruitment of myeloid derived suppressor cells (MDSCs) and B cells in PDA via cytokines increased due to hypoxia. PSCs also increase collagen secretion in response to HIF-1α, which promotes a fibrotic stroma that alters T cell homing and migration. In hypoxic environments, B cells contribute to cytotoxic T cell exhaustion and produce chemokines to attract more immunosuppressive regulatory T cells. MDSCs inhibit T cell metabolism by hoarding key amino acids, modulate T cell homing by cleaving L-selectin, and prevent T cell activation by increasing PD-L1 expression. Immunosuppressive M2 phenotype macrophages promote T cell anergy via increased nitric oxide (NO) and decreased arginine in hypoxia. Increased numbers of regulatory T cells are seen in hypoxia which prevent effector T cell activation through cytokine production and increased CTLA-4. Effective immunotherapy for pancreatic adenocarcinoma and other solid tumors will need to help counteract the immunosuppressive nature of hypoxia-induced changes in the tumor microenvironment. Promising studies will look at combination therapies involving checkpoint inhibitors, chemokine inhibitors, and possible targeting of hypoxia. While no model is perfect, assuring that models incorporate the effects of hypoxia on cancer cells, stromal cells, and effector immune cells will be crucial in developing successful therapies.

Synthesis of Gemcitabine-Threonine Amide Prodrug Effective on Pancreatic Cancer Cells with Improved Pharmacokinetic Properties

To investigate the amino acid transporter-based prodrug anticancer strategy further, several amino acid-conjugated amide gemcitabine prodrugs were synthesized to target amino acid transporters in pancreatic cancer cells. The structures of the synthesized amino acid-conjugated prodrugs were confirmed by ¹H-NMR and LC-MS. The pancreatic cancer cells, AsPC1, BxPC-3, PANC-1 and MIAPaCa-2, appeared to overexpress the amino acid transporter LAT-1 by conventional RT-PCR. Among the six amino acid derivatives of gemcitabine, threonine derivative of gemcitabine (Gem-Thr) was more effective than free gemcitabine in the pancreatic cancer cells, BxPC-3 and MIAPaCa-2, respectively, in terms of anti-cancer effects. Furthermore, Gem-Thr was metabolically stable in PBS (pH 7.4), rat plasma and liver microsomal fractions. When Gem-Thr was administered to rats at 4 mg/kg i.v., Gem-Thr was found to be successfully converted to gemcitabine via amide bond cleavage. Moreover, the Gem-Thr showed the increased systemic exposure of formed gemcitabine by 1.83-fold, compared to free gemcitabine treatment, due to the significantly decreased total clearance (0.60 vs. 4.23 mL/min/kg), indicating that the amide prodrug approach improves the metabolic stability of gemcitabine in vivo. Taken together, the amino acid transporter-targeting gemcitabine prodrug, Gem-Thr, was found to be effective on pancreatic cancer cells and to offer an efficient potential means of treating pancreatic cancer with significantly better pharmacokinetic characteristics than gemcitabine.