Anders Holmberg

Ultrastructural changes in the gracile nucleus of the rat after sciatic nerve transection

SummaryUltrastructural changes in the gracile nucleus of the rat have been examined after peripheral nerve injury. The sciatic nerve of adult rats was transected at mid-thigh level, and after survival times ranging from 1 day to 32 weeks sections from the gracile nucleus were prepared for electron microscopic examination. Unoperated animals served as controls. Atypical profiles were regularly observed in the experimental cases at post-operative survival times from 3 days up to 32 weeks. It was sometimes not possible to classify these as pre-terminal axons or terminals, because synaptic contacts could not be identified. The two most common changes throughout the entire post-operative period were greatly expanded myelinated axons, or unmyelinated profiles containing numerous mitochondria, osmiophilic dense bodies and vacuoles. Atypical profiles were occasionally observed in unoperated control animals. The results clearly show that various types of degenerative changes occur in the gracile nucleus after peripheral nerve injury. These changes differ markedly from previously described transganglionic changes in other systems. It cannot be excluded that some of the changes reflect growth-related reactions, although the typical features of axon regeneration could not be found.

A novel somatostatin conjugate with a high affinity to all five somatostatin receptor subtypes.

Somatostatin receptors (SRS, five subtypes) are expressed in a variety of human tumors, including most tumors of neuroendocrine origin, breast tumors, certain brain tumors, renal cell tumors, lymphomas, and prostate cancer. Somatostatin (SMS) triggers cytostatic and cytotoxic effects and has a general inhibitory effect on secretion mediated through its interaction with SRS. That is the basis for its use in the treatment of SRS‐positive tumors. Radiolabeled SMS analogs can also be used for systemic radiotherapy and for diagnostic investigations.

The use of Butea superba (Roxb.) compared to sildenafil for treating erectile dysfunction.

Study Type – Therapy (case control) Level of Evidenceu20033b

Prostate cancer cell lines lack amplification : Overexpression of HER2

The potential overexpression of HER2 in prostate cancer cells has attended significant interest during the past few years, both as potential target for HER2 pathway focused therapy and as a mechanism involved in the progression to androgen independence. Conflicting results have been reported concerning HER2 status on clinical material, differences which generally have been attributed to methodological differences. Nevertheless, HER2 has been utilized for targeted therapy of prostate cancer in a number of preclinical studies and is still regarded as an exciting target molecule. In this study, the HER2 status of three widely used prostate cancer cell lines and corresponding xenografts has been analysed. By use of validated and FDA approved analytical staining techniques none of these cell lines or xenografts were shown to overexpress/amplify HER2, as demonstrated by immunohistochemistry and fluorescense in situ hybridization. These findings are important for the interpretation and understanding of the therapeutic effects when developing drugs targeting HER2 in prostate cancer cell lines and also emphasize the importance of using broad and validated analytical techniques.

The effect of sciatic nerve transection on myelinated fibers in the L5 dorsal root and lumbar dorsal column

SummaryThe occurrence of Marchi-positive structures (MPS) in the L5 dorsal root and lumbar dorsal column was examined 1–18 weeks after unilateral sciatic nerve transection in rats, and compared to the occurrence of MPS during Wallerian degeneration seen after transection of L4 and L5 dorsal roots. There was an increasing number of MPS centrally to the junction between the peripheral (PNS) and central nervous system (CNS) and in the lumbar dorsal column ipsilateral to sciatic nerve transection throughout the examined time period. In the portion of the root distal to the PNS-CNS junction MPS were rare before 12 weeks postoperatively after which time small groups of MPS appeared. At all stages the incidence of MPS was just a fraction of that seen during Wallerian degeneration. From these observations it is inferred that few ganglion cells with myelinated central processes undergo complete disintegration after peripheral nerve transection. In addition, some of the myelinated central ganglion cell processes appear to be more severely affected proximal to the PNS-CNS junction than distally to it.

Somatostatin Derivative (smsDX) Targets Cellular Metabolism in Prostate Cancer Cells after Androgen Deprivation Therapy

Cancer cell metabolism responsive to androgen deprivation therapy (ADT) may be involved in the development and progression of prostate cancer and the ultimate failure of androgen-deprivation therapy. To investigate the metabolism regulation effects on androgen-independent growth of prostate cancer, an established LNCaP-s cell model that resembles the clinical scenario of castration-resistant prostate cancer (CRPC), was used in this current study. This cell line was cultured from androgen-sensitive LNCaP parental cells, in an androgen-reduced condition, resembling clinical androgen deprivation therapy. To assess the effects of smsDX on the invasiveness of prostate cancer cells we used wound healing assay and Matrigel™ invasion assay. We evaluated differentially expressed proteins of the parental LNCaP cells and LNCaP-s cells after ADT by means of two-dimensional gel electrophoresis (2-DE) followed by MALDI-TOF mass spectrometric analysis. The covered area in the wound and the number of cells invading through a Matrigel chamber were significantly smaller for cells treated with smsDX than they were for control cells treated with vehicle. 56 proteins were found differentially expressed in LNCaP-s cells compared to LNCaP cells, majority of them were down-regulated after ADT treatment. 104 proteins of LNCaP cells and 86 in LNCaP-s cells, separately, were found differentially expressed after treatment with smsDX, When we explored these protein functions within the website UniProtKB/Swiss-Prot, surprisingly, most of the proteins were found to be involved in the cellular metabolism and mitochondrial function regulation. LNCaP-s as potential metastatic androgen-independent cancer cells, its metabolism and mitochondrial functions could be altered by a new somatostatin derivative smsDX, the smsDX regulatory effects on metabolism in LNCaP-s deliver more therapeutic information with the treatment of CRPC.

Somatostatin Derivate (smsDX) Attenuates the TAM-Stimulated Proliferation, Migration and Invasion of Prostate Cancer via NF-κB Regulation

Tumor development and progression are influenced by macrophages of the surrounding microenvironment. To investigate the influences of an inflammatory tumor microenvironment on the growth and metastasis of prostate cancer, the present study used a co-culture model of prostate cancer (PCa) cells with tumor-associated macrophage (TAM)-conditioned medium (MCM). MCM promoted PCa cell (LNCaP, DU145 and PC-3) growth, and a xenograft model in nude mice consistently demonstrated that MCM could promote tumor growth. MCM also stimulated migration and invasion in vitro. Somatostatin derivate (smsDX) significantly attenuated the TAM-stimulated proliferation, migration and invasion of prostate cancer. Immunohistochemistry revealed that NF-κB was over-expressed in PCa and BPH with chronic inflammatory tissue specimens and was positively correlated with macrophage infiltration. Further investigation into the underlying mechanism revealed that NF-κB played an important role in macrophage infiltration. SmsDX inhibited the paracrine loop between TAM and PCa cells and may represent a potential therapeutic agent for PCa.

Application of accelerator mass spectrometry to macromolecules: preclinical pharmacokinetic studies on a polybisphosphonate

Data on the use of accelerator mass spectrometry (AMS) in conjunction with in vivo studies of macromolecular drugs are scarce. The present study shows the versatility of this technique when investigating the pharmacokinetics (PK) of a macromolecular drug candidate, a polybisphosphonate conjugate (ODX). The aforementioned is a polymer (molecular weight ~30u2009kDa) constituting a carbohydrate backbone with covalently linked ligands (aldendronate and aminoguanidine) and is intended for treatment of osteoporosis and the therapy of bone metastasis from prostate cancer. The conjugate is prepared through partial oxidation of the carbohydrate and sequential coupling of the ligands by reductive amination. (14)C was incorporated in the conjugate by means of coupling a commercially available (14)C-lysine in the conjugation sequence. Fifteen rats were injected intravenously with (14)C-labelled ODX (150u2009µg, 14u2009Bq/rat) and blood samples were collected at 1, 2, 4, 6, and 24u2009h post-injection (3 rats/time point). Liver, spleen and kidney samples were collected at 4 and 24u2009h post-injection. Blood from each time point (triplicate) were collected for AMS measurement determining the isotopic ratio ((14)C/(12)C) and consequently the drug concentration in blood. ODX showed a transient presence in blood circulation; 93% of the total dose was cleared from the circulation within 1u2009h. The half-life after 1u2009h was estimated to be about 3u2009h; 0.7% of the administered (14)C dose of ODX remained in circulation after 24u2009h. The major (14)C accumulation was in the liver, the spleen and the kidneys indicating the probable route of metabolism and excretion. This study demonstrates the versatility of AMS for pharmacological in vivo studies of macromolecules. Labelling with (14)C is relatively simple, inexpensive and the method requires minimal radioactivity, eliminating the need for radioprotection precautions in contrast to methods using scintillation counting.