SWITCH: A Randomised, Sequential, Open-label Study to Evaluate the Efficacy and Safety of Sorafenib-sunitinib Versus Sunitinib-sorafenib in the Treatment of Metastatic Renal Cell Cancer

BACKGROUND

Understanding how to sequence targeted therapies for metastatic renal cell carcinoma (mRCC) is important for maximisation of clinical benefit.

OBJECTIVES

To prospectively evaluate sequential use of the multikinase inhibitors sorafenib followed by sunitinib (So-Su) versus sunitinib followed by sorafenib (Su-So) in patients with mRCC.

DESIGN, SETTING, AND PARTICIPANTS

The multicentre, randomised, open-label, phase 3 SWITCH study assessed So-Su versus Su-So in patients with mRCC without prior systemic therapy, and stratified by Memorial Sloan Kettering Cancer Center risk score (favourable or intermediate).

INTERVENTION

Patients were randomised to sorafenib 400mg twice daily followed, on progression or intolerable toxicity, by sunitinib 50mg once daily (4 wk on, 2 wk off) (So-Su), or vice versa (Su-So).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was improvement in progression-free survival (PFS) with So-Su versus Su-So, assessed from randomisation to progression or death during second-line therapy. Secondary endpoints included overall survival (OS) and safety.

RESULTS AND LIMITATIONS

In total, 365 patients were randomised (So-Su, n=182; Su-So, n=183). There was no significant difference in total PFS between So-Su and Su-So (median 12.5 vs 14.9 mo; hazard ratio [HR] 1.01; 90% confidence interval [CI] 0.81-1.27; p=0.5 for superiority). OS was similar for So-Su and Su-So (median 31.5 and 30.2 mo; HR 1.00, 90% CI 0.77-1.30; p=0.5 for superiority). More So-Su patients than Su-So patients reached protocol-defined second-line therapy (57% vs 42%). Overall, adverse event rates were generally similar between the treatment arms. The most frequent any-grade treatment-emergent first-line adverse events were diarrhoea (54%) and hand-foot skin reaction (39%) for sorafenib; and diarrhoea (40%) and fatigue (40%) for sunitinib.

CONCLUSIONS

Total PFS was not superior with So-Su versus Su-So. These results demonstrate that sorafenib followed by sunitinib and vice versa provide similar clinical benefit in mRCC.

PATIENT SUMMARY

We investigated if total progression-free survival (PFS) is improved in patients with advanced/metastatic kidney cancer who are treated with sorafenib and then with sunitinib (So-Su), compared with sunitinib and then sorafenib (Su-So). We found that total PFS was not improved with So-Su compared with Su-So, but both treatment options were similarly effective in patients with advanced/metastatic kidney cancer.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT00732914, www.clinicaltrials.gov.

Anatomoclinical study of 30 cases of sclerosing sweat duct carcinomas (microcystic adnexal carcinoma, syringomatous carcinoma and squamoid eccrine ductal carcinoma)

BACKGROUND

Microcystic adnexal carcinoma (MAC), syringomatous carcinoma (SC) and "Squamoid eccrine ductal carcinoma" (SEDC) are rare sclerosing adnexal tumours.

OBJECTIVE

To understand the histogenesis of these tumours and possible clinical implications.

METHODS

We conducted a retrospective study of 30 cases, 18 MAC, 5 SC and 7 SEDC reviewed and classified by a panel of dermatopathology experts, with immunohistochemical analysis of keratins, including K77, a new keratin specific of eccrine ducts, and PHLDA1 expressed in adnexal structures.

RESULTS

There was a strong female predominance, with only five cases occurring in men. Patients with MAC and SC were younger (mean age 56 and 47 years) than those with SEDC (mean age 81 years). The most common localization was the cheek in SC and SEDC and the periocular area in MAC. Two cases of SEDC were found in organ transplant patients. No recurrence or metastases were observed after complete surgery of MAC, or SC (mean follow-up 7.2 years and 4.7 years), whereas one case of SEDC recurred and another could not be fully excised. MAC and SC had similar histological features, except for cysts. In MAC, calcifications, granulomas, connection to follicles, keratin expression pattern, PHLDA1 positivity and K77 negativity indicated a follicular histogenesis, whereas in SC, K77 positivity and keratin expression pattern were consistent with a differentiation towards eccrine apparatus. SEDC was composed of strands centred by ducts and nests with squamous differentiation and displayed K77 ductal positivity in all cases, a finding consistent with an eccrine origin.

CONCLUSION

Our study demonstrated that MAC and SC have similar clinical characteristics, although histogenesis differs and show arguments for the individualization of SEDC.

Immediate and transient phosphorylation of the heat shock protein 27 initiates chemoresistance in prostate cancer cells

Drug resistance minimizes the effects of prostate cancer (PC) chemotherapy with docetaxel and is generally considered to be associated with the expression of heat shock protein (HSP) 27 including various cytoprotective pathways. In the present study, we investigated the effects of HSP27 phosphorylation on PC cell growth underlying docetaxel treatment. Cell counting revealed significantly reduced cell growth during docetaxel treatment as a result of both activation of mitogen-activated protein kinase p38 (MAPK p38) and protein kinase D1 (PKD1), and, most importantly, the overexpression of the phosphorylation-mimicking mutant HSP27-3D. Further analysis revealed a docetaxel-dependent induction of HSP27 accompanied by an initial phosphorylation and rapid dephosphorylation of the protein. Based on the data, we can conclude that phosphorylation of HSP27 protein is a crucial mechanism in the initiation of chemoresistance in PC. Moreover, the results indicate a key impact of HSP27 on viability and proliferation of PC cells underlying anticancer therapy. The protective function depends on the initial phosphorylation status of HSP27 and represents a putative co-therapeutic target to prevent chemoresistance during docetaxel therapy.

Transcriptional regulation of urate transportosome member SLC2A9 by nuclear receptor HNF4α

Renal tubular handling of urate is realized by a network of uptake and efflux transporters, including members of drug transporter families such as solute carrier proteins and ATP-binding cassette transporters. Solute carrier family 2, member 9 (SLC2A9), is one key factor of this so called "urate transportosome." The aim of the present study was to understand the transcriptional regulation of SLC2A9 and to test whether identified factors might contribute to a coordinated transcriptional regulation of the transporters involved in urate handling. In silico analysis and cell-based reporter gene assays identified a hepatocyte nuclear factor (HNF)4α-binding site in the promoter of SLC2A9 isoform 1, whose activity was enhanced by transient HNF4α overexpression, whereas mutation of the binding site diminished activation. HNF4α overexpression induced endogenous SLC2A9 expression in vitro. The in vivo role of HNF4α in the modulation of renal SLC2A9 gene expression was supported by findings of quantitative real-time RT-PCR analyses and chromatin immunoprecipitation assays. Indeed, mRNA expression of SLC2A9 and HNF4α in human kidney samples was significantly correlated. We also showed that in renal clear cell carcinoma, downregulation of HNF4α mRNA and protein expression was associated with a significant decline in expression of the transporter. Taken together, our data suggest that nuclear receptor family member HNF4α contributes to the transcriptional regulation of SLC2A9 isoform 1. Since HNF4α has previously been assumed to be a modulator of several urate transporters, our findings support the notion that there could be a transcriptional network providing synchronized regulation of the functional network of the urate transportosome.

Heat-shock protein HSPB1 attenuates microRNA miR-1 expression thereby restoring oncogenic pathways in prostate cancer cells

BACKGROUND

Heat-shock proteins (HSPs) as well as microRNAs have been identified to orchestrate crucial mechanisms in prostate cancer (PCa) progression and treatment resistance. Due to cytoprotective properties of HSPB1 we analyzed molecular mechanisms of drug resistance in PCa cell culture systems, and notably found HSPB1 functionality linked to microRNA miR-1 activities.

MATERIALS AND METHODS

HSPB1 and miR-1 levels were genetically modified in PCa cell lines and alterations in molecular and cellular responses were assessed by quantitative reverse transcription/polymerase chain reaction, western blotting, and proliferation assays.

RESULTS

Our data provided for the first time evidence that HSPB1 regulates miR-1 expression, and subsequently restores oncogenic signaling pathways of androgen receptor (AR) and transforming growth factor β1 (TGFB1).

CONCLUSION

Our data point towards HSPB1 and miR-1 involvement in development of castration-resistant PCa and therefore represent promising targets for anticancer therapy of advanced PCa.

Automatic Turgor Pressure Recording in Plant Cells

An automatically-regulated pressure probe is described, which facilitates the direct and continuous measurement of turgor pressure and water relation parameters in plant cells. An optoelectronic sensor drives a feed back system so that the position of the oil/cell sap interface in the measur­ing capillary remains constant. The sensor is easily applied to most measurement set-ups by mounting it on a focusing screen connected to the microscope used for observation. The position of the oil/cell sap boundary is sensed by its movement along the image of the capillary on the screen and can be set to any appropriate position. The optical coupling of the regulation signal is advantageous because it leaves the experimenter free to measure the electrical or other parameters of the cell. Experiments on cells of Eremosphaera viridis have shown that the device allows much faster and more exact measurements of water rela­tion parameters, and over longer periods, than the earlier method.

Rotating-Field-Induced Rotation and Measurement of the Membrane Capacitance of Single Mesophyll Cells of Avena sativa

Rotation of single cells (mesophyll protoplasts of Avena sativa) induced by a planar, homogeneous rotating field has been observed at a frequency of 20-40 kHz (conductivity of the external mannitol solution 6x 10-5 Ω-1 cm-1). This variation in optimum frequency is largely due to an inverse dependence on cell radius. Rotation direction is opposite to that of the field, and can be reversed at will by reversing the field. The maximum speed of cell spinning was a few cycles per second (and thus always much slower than that of the field) and was proportional to the square of the amplitude of the field.

The rotation of a single cell in a rotating field is expected on the basis of the dipole-dipole theory developed by Holzapfel et al., (J. Membrane Biol. 67, 1-14 (1982)), for multi-cell rotation. Measurements of the dependence of optimum applied field frequency on medium conductivity indicate that the dipole is generated by interfacial (Maxwell-Wagner) polarization. The required frequency is a linear function of the conductivity of the external solution. This relationship is used to derive a value for the specific membrane capacitance. Further applications of this technique for cell and membrane research are discussed.

Untersuchungen über den Kaliumtransport bei Escherichia coli B / Potassium Transport in Escherichia coli B

The stationary intracellular potassium concentration in E. coli B 525 has been studied as a function of the extracellular potassium and sodium concentrations.

The ratio of extracellular to intracellular potassium concentration is shown to be a linear function of the extracellular potassium concentration if the extracellular sodium concentration is low (20 mmoles/l). In the case of high sodium concentration (100 mmoles/l) the ratio is independent of the extracellular potassium concentration if the potassium concentration is below 1,2 mmoles/l.

In order to describe the distribution of potassium uniformly over the whole range of the extracellular potassium and sodium concentrations a carrier system with two sites has to be supposed.

II. Regelmäßige Bandenstruktur in peritrophischen Membranen / Periodically Alternating Structure of Peritrophic Membranes

Autoradiographic investigations on the structure of the perithrophic membranes of Calliphora erythrocephala Mg. showed regular alternating stripes having different affinities for anions and cations. This structure may have the qualities of the theoretically discussed mosaic membran.

High Yields of DNA-Transfer into Mouse L-Cells by Electropermeabilization

DNA transfection in mouse L-cells was performed by means of the electropermeabilization technique (U. Zimmermann, G. Pilwat, and F. Riemann, Z. Naturforsch. 29, 304 (1974)). The plasmid pSV 2-neo used leads to neomycin-resistance in stably transfected L-cells. Optimized conditions resulted in high yields of clones at relatively low DNA concentration. The influence of temperature during pulse application and during the subsequent resealing process as well as the field parameters and medium com­position are discussed.

Unterchungen über den Transport von Stoffen durch peritrophische Membranen / Investigation of the Transport of Material through Peritrophic Membranes

The tubular peritrophic membranes of Calliphora are formed by the secreting cells of the proventriculus at a rate of 3.5 ± 1 mm per hour. It has been estimated that each of these cells produces its own weight in membrane material in about one day.

Autoradiography of peritrophic membranes from flies injected with glucose-C 14 show cross bands as well as longitudinal bands, indicating a periodic incorporation of radioactive material and therefore a different chemical composition, which may be of importance for transport phenomena.

Organspezifische Applikation von pharmazeutisch aktiven Substanzen über zellulare Trägersysteme / Organ Specific Application of Drugs by Means of Cellular Capsule Systems

It is suggested to use living cells (red blood cells, lymphocytes and leucocytes) as drug delivery systems for temporal and spatial drug administration in human therapeutics and diagnosis. The effectiveness of drug loaded cells is demonstrated for the drug methotrexate which is used in cancer treatment.

Red blood cells are loaded with methotrexate using the dielectric breakdown technique. Dielectric breakdown leads to a transient increase of permeability of the cell membrane. Red blood cells loaded with tritium-labelled methotrexate were injected into mice and the activity level was measured in several organs as a function of time. It is shown that with this drug delivery system more than 50% of the drug (after 10 min) can be accumulated in the liver and that a high activity level can be sustained in this organ for more than 3 hours. On the other hand, administration of this drug by injecting solutions in the usual manner leads only to an 25% accumulation of methotrexate (after 10 min) in the liver. The drug is excreted completely after 1 to 2 hours.

It is proposed to load red blood cells simultaneously with para-or ferromagnetic substances to obtain organ-specificity for any selected site of the body.

Untersuchungen über den Kaliumtransport in E. coli B

An intracellular concentration of potassium in E. coli B 525 stationary for several hours is only attained by addition of the essential amino acids histidine and leucine, or ammonium chloride, to the incubation medium. The level of the stationary intracellular potassium concentration is dependent upon the concentration of these substances.

The two other combinations of the essential amino acids (leucine/methionine and histidine/methionine) and the single amino acids show no stabilization effect upon the internal stationary potassium level.

In the case of the wild type B 163, the instability of the stationary internal potassium concentration, and the corresponding effect of the above mentioned substances, is not so significant. Therefore the instability which is observed in the case of B 525 can be deduced from the mutation.

The contemporary role of ablative treatment approaches in the management of renal cell carcinoma (RCC): focus on radiofrequency ablation (RFA), high-intensity focused ultrasound (HIFU), and cryoablation

INTRODUCTION

Currently, most of renal tumors are small, low grade, with a slow growth rate, a low metastatic potential, and with up to 30 % of these tumors being benign on the final pathology. Moreover, they are often diagnosed in elderly patients with preexisting medical comorbidities in whom the underlying medical conditions may pose a greater risk of death than the small renal mass. Concerns regarding overdiagnosis and overtreatment of patients with indolent small renal tumors have led to an increasing interest in minimally invasive, ablative as an alternative to extirpative interventions for selected patients.

OBJECTIVE

To provide an overview about the state of the art in radiofrequency ablation (RFA), high-intensity focused ultrasound, and cryoablation in the clinical management of renal cell carcinoma.

METHODS

A PubMed wide the literature search of was conducted.

RESULTS

International consensus panels recommend ablative techniques in patients who are unfit for surgery, who are not considered candidates for or elect against elective surveillance, and who have small renal masses. The most often used techniques are cryoablation and RFA. These ablative techniques offer potentially curative outcomes while conferring several advantages over extirpative surgery, including improved patient procedural tolerance, faster recovery, preservation of renal function, and reduction in the risk of intraoperative and postsurgical complications. While it is likely that outcomes associated with ablative modalities will improve with further advances in technology, their application will expand to more elective indications as longer-term efficacy data become available.

CONCLUSION

Ablative techniques pose a valid treatment option in selected patients.