p38 Mediates Resistance to FGFR Inhibition in Non-Small Cell Lung Cancer

FGFR signalling is one of the most prominent pathways involved in cell growth and development as well as cancer progression. FGFR1 amplification occurs in approximately 20% of all squamous cell lung carcinomas (SCC), a predominant subtype of non-small cell lung carcinoma (NSCLC), indicating FGFR as a potential target for the new anti-cancer treatment. However, acquired resistance to this type of therapies remains a serious clinical challenge. Here, we investigated the NSCLC cell lines response and potential mechanism of acquired resistance to novel selective FGFR inhibitor CPL304110. We found that despite significant genomic differences between CPL304110-sensitive cell lines, their resistant variants were characterised by upregulated p38 expression/phosphorylation, as well as enhanced expression of genes involved in MAPK signalling. We revealed that p38 inhibition restored sensitivity to CPL304110 in these cells. Moreover, the overexpression of this kinase in parental cells led to impaired response to FGFR inhibition, thus confirming that p38 MAPK is a driver of resistance to a novel FGFR inhibitor. Taken together, our results provide an insight into the potential direction for NSCLC targeted therapy.

Evaluation of the Role of ITGBL1 in Ovarian Cancer

In our previous microarray study we identified two subgroups of high-grade serous ovarian cancers with distinct gene expression and survival. Among differentially expressed genes was an Integrin beta-like 1 (ITGBL1), coding for a poorly characterized protein comprised of ten EGF-like repeats. Here, we have analyzed the influence of ITGBL1 on the phenotype of ovarian cancer (OC) cells. We analyzed expression of four putative ITGBL1 mRNA isoforms in five OC cell lines. OAW42 and SKOV3, having the lowest level of any ITGBL1 mRNA, were chosen to produce ITGBL1-overexpressing variants. In these cells, abundant ITGBL1 mRNA expression could be detected by RT-PCR. Immunodetection was successful only in the culture media, suggesting that ITGBL1 is efficiently secreted. We found that ITGBL1 overexpression affected cellular adhesion, migration and invasiveness, while it had no effect on proliferation rate and the cell cycle. ITGBL1-overexpressing cells were significantly more resistant to cisplatin and paclitaxel, major drugs used in OC treatment. Global gene expression analysis revealed that signaling pathways affected by ITGBL1 overexpression were mostly those related to extracellular matrix organization and function, integrin signaling, focal adhesion, cellular communication and motility; these results were consistent with the findings of our functional studies. Overall, our results indicate that higher expression of ITGBL1 in OC is associated with features that may worsen clinical course of the disease.

Characteristics of in Vivo Model Systems for Ovarian Cancer Studies

An understanding of the molecular pathogenesis and heterogeneity of ovarian cancer holds promise for the development of early detection strategies and novel, efficient therapies. In this review, we discuss the advantages and limitations of animal models available for basic and preclinical studies. The fruit fly model is suitable mainly for basic research on cellular migration, invasiveness, adhesion, and the epithelial-to-mesenchymal transition. Higher-animal models allow to recapitulate the architecture and microenvironment of the tumor. We discuss a syngeneic mice model and the patient derived xenograft model (PDX), both useful for preclinical studies. Conditional knock-in and knock-out methodology allows to manipulate selected genes at a given time and in a certain tissue. Such models have built our knowledge about tumor-initiating genetic events and cell-of-origin of ovarian cancers; it has been shown that high-grade serous ovarian cancer may be initiated in both the ovarian surface and tubal epithelium. It is postulated that clawed frog models could be developed, enabling studies on tumor immunity and anticancer immune response. In laying hen, ovarian cancer develops spontaneously, which provides the opportunity to study the genetic, biochemical, and environmental risk factors, as well as tumor initiation, progression, and histological origin; this model can also be used for drug testing. The chick embryo chorioallantoic membrane is another attractive model and allows the study of drug response.

Ballistic-choreic movements as the presenting feature of renal cancer

BACKGROUND

The paraneoplastic syndromes can involve multiple areas of the central nervous system and result in a variety of neurological symptoms. To our knowledge, severe, rapidly progressive, and drug-resistant ballistic-choreic movements have not been previously described as the presenting feature of renal cell carcinoma.

PATIENT AND METHODS

A previously healthy 55-year-old man developed limb ballismus and involuntary choreic movements of his face over several weeks. Extensive laboratory, diagnostic, and radiographic studies failed to reveal a cause, until an abnormality on a chest x-ray film prompted a search for a primary neoplasm and a final diagnosis of renal cell carcinoma. High doses of medications traditionally used to treat choreic disorders had no effect on the abnormal movements. A biopsy specimen of the basal ganglia showed focal encephalitic changes but no malignant neoplasm.

CONCLUSIONS

Whereas prior cases of paraneoplastic syndromes with chorea have been reported in other forms of cancer, our case was significant because, to our knowledge, renal cell carcinoma has not been previously reported in association with this syndrome. Furthermore, the chorea was categorically resistant to pharmacological treatment, and the movement disorder was the initial and only focal neurological feature of the primary illness.

Inhibition of the accelerative effects of testosterone on hamster facial nerve regeneration by the antiandrogen flutamide

We have previously demonstrated that systemic administration of testosterone propionate (TP) to adult hamsters accelerates the rate of facial nerve regeneration following crush axotomy of the facial nerve at its exit from the stylomastoid foramen. In this study, we utilized flutamide, a potent nonsteroidal antiandrogen, in conjunction with radioisotopic labeling procedures for the assessment of facial nerve regeneration rates to test the hypothesis that TP exerts its accelerative effects on facial nerve regeneration through a receptor-mediated mechanism. Castrated adult male hamsters were subjected to right facial nerve crush axotomies and divided into three groups of axotomized animals: castrate plus one subcutaneous TP implant plus daily injections of flutamide, castrate plus one subcutaneous TP implant plus vehicle injections, and castrate only plus sham implant and vehicle injections. There were two postoperative timepoints: 4 and 7 days. In agreement with previous studies, systemic administration of TP resulted in an approximately 26% increase in the rate of regeneration of the fastest growing population of axons. Exposure to flutamide completely abolished the TP-induced accelerative effects on facial nerve regeneration rate. As a bioassay for the effectiveness of systemic administration of flutamide by subcutaneous injection, seminal vesicle weights were collected from all groups at the end of the postoperative time and compared as a percentage of the seminal vesicle weights of intact (nongonadectomized) male control animals. Castration greatly reduced seminal vesicle weights, whereas exogenous TP restored the seminal vesicle weights to those of the intact male. Flutamide blocked the effects of exogenous TP on seminal vesicle weights and reduced them to castrate levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Testosterone regulation of the regenerative properties of injured rat sciatic motor neurons

We have previously demonstrated that systemic administration of testosterone differentially regulates the regenerative properties of injured hamster facial motor neurons, which are androgen receptor-containing cranial motor neurons. In this investigation, the hypothesis that testosterone alters the regenerative properties of rat sciatic motor neurons, which are androgen receptor-containing spinal motor neurons, was tested using fast axonal transport of radioactively labeled proteins to assess sciatic nerve regeneration. Adult castrated male rats were subjected to crush axotomy of the sciatic nerve at the level of the gemelli tendons (mid-thigh). One-half of the axotomized animals received subcutaneous implants of testosterone propionate (TP), with the remainder of the animals sham implanted with blank capsules. The outgrowth distances of the leading axons were measured at 5, 6, 7, and 11 days postoperative. Linear regression analysis was accomplished, with the slope of the line representing the regeneration rate and the x-intercept the initial delay of sprout formation. Systemic administration of testosterone resulted in a 13% increase in the rate of regeneration, relative to the control, -TP group. Outgrowth distances were significantly increased in the +TP group only in the later stages of regeneration. However, TP did not shorten the delay in sprout formation in regenerating sciatic motor neurons, but instead produced a small prolongation in the delay time. This pattern of hormonal regulation of the regenerative properties of spinal motoneurons is similar to that previously found in cranial motoneurons. The prolongation of the initial delay may have been a factor in the lack of significant outgrowth distances during the early stages of regeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

Testosterone differentially regulates the regenerative properties of injured hamster facial motoneurons

We have previously demonstrated that systemic administration of testosterone accelerates functional recovery, as measured behaviorally, from facial paralysis induced by facial nerve crush axotomy in gonadectomized adult male hamsters. In this investigation, the hypothesis that testosterone enhances return of motor function by increasing the rate of axonal regeneration following injury was tested using fast axonal transport of radioactively labeled proteins to assess facial nerve regeneration. Adult castrated and intact males, and intact females, were subjected to right facial nerve crush axotomy at the stylomastoid foramen. One-half of the axotomized animals in each group received subcutaneous implants of testosterone, with the remainder of the animals sham implanted. Systemic administration of testosterone resulted in a 26-30% increase in the rate of regeneration of the fastest growing population of axons in the male experimental groups, regardless of whether the animal was castrated or not. This rate increase is similar to that observed in the conditioning lesion paradigm utilized by others. In the females, testosterone had a significant, but less pronounced, effect on the rate of axonal regeneration, which may be due in part to inherent gender-related differences in regenerative properties of facial motoneurons. A surprising finding of this study was that no shortening of the delay of sprout formation by testosterone was observed across the various experimental groups. These data suggest that the mechanism by which gonadal steroids act in the injured nervous system is partly through the differential regulation of the regenerative properties of the injured cell, presumably via hormone receptor-mediated action at the level of the neuronal genome.

Testosterone-induced acceleration of recovery from facial paralysis in male hamsters: temporal requirements of hormone exposure

In this study, the temporal requirements of testosterone propionate (TP) exposure necessary for acceleration of recovery from facial paralysis to occur following facial nerve crush were examined. For each of two series of experiments, adult castrated male hamsters were subjected to crush axotomies of the facial nerve at its exit from the stylomastoid foramen. In the first experimental paradigm, one-half of the animals with facial nerve crush axotomies received subcutaneous TP capsules beginning on postoperative (PO) day 6 and continuing throughout the regeneration period, with the remainder of the animals sham implanted. The results indicate that, without the early exposure to TP, the accelerative effects of the hormone on facial nerve regeneration were abolished. In the second experimental paradigm, one-half of the animals with facial nerve crush axotomies received subcutaneous TP implants immediately after the crush surgeries and until PO day 7, with the remainder of the animals sham implanted. The results indicate that an early, discontinuous dose of TP immediately after crush surgeries was sufficient to produce a partial accelerative effect on the return of facial nerve function. It is hypothesized from these findings that there is a priming effect of TP that is exerted at the level of the neuron, temporally precedes behavioral recovery by a week or more and is critical to subsequent acceleration of recovery from facial paralysis.

Testosterone-induced acceleration of recovery from facial paralysis following crush axotomy of the facial nerve in male hamsters

In this study, the effects of testosterone propionate (TP) on recovery from facial paralysis following crush axotomy of the facial nerve in male hamsters were examined. In the first experiment, TP (5 mg/ml sesame oil; 0.1 ml) was injected subcutaneously and on alternate days in one-half of the animals subjected to crush axotomies of the facial nerve, with the second half receiving vehicle alone. An accelerative effect of TP on recovery from facial paralysis was observed near the end of the first and beginning of the second week after crush axotomy. When the dosage and frequency were doubled in the next experiment, a greater accelerative effect of TP on recovery from facial paralysis was observed. In the last experiment, castrated animals were used in order to eliminate the endogenous source of the hormone and two different modes of hormone administration, TP implants vs TP injections, were compared. The results of that experiment indicate that continuous exposure to the hormone, in the form of subcutaneous implants of 100% crystalline TP, had the most pronounced effect on acceleration of recovery from facial paralysis. In addition, no differences in the responses of the castrated, axotomized animals and the normal, axotomized animals were found. This suggests that the presence of endogenous hormone contributes little to the acceleration of functional recovery observed with TP. Finally, the time course of the accelerative effect of TP suggests that the hormone is acting primarily at the level of the facial neuron, which contains androgen receptors, and perhaps secondarily at the level of the facial muscles, which are also known to contain androgen receptors.