Longevity of cold-exposed rats: a reevaluation of the "rate-of-living theory"

It has been postulated that increased energy expenditure results in shortened survival. To test this "rate-of-living theory" we examined the effect of raising energy expenditure by means of cold exposure on the longevity of rats. Male 6-mo-old SPF Long-Evans rats were gradually accustomed to immersion in cool water (23 degrees C). After 3 mo they were standing in the cool water for 4 h/day, 5 days/wk. They were maintained on this program until age 32 mo. The cold exposure resulted in a 44% increase in food intake (P less than 0.001). Despite their greater food intake, the cold-exposed rats' body weights were significantly lower than those of control animals from age 11 to 32 mo. The average age at death of the cold-exposed rats was 968 +/- 141 days compared with 923 +/- 159 days for the controls. The cold exposure appeared to protect against neoplasia, particularly sarcomas; only 24% of the necropsied cold-exposed rats had malignancies compared with 57% for the controls. The results of this study provide no support for the concept that increased energy expenditure decreases longevity.     

Hyperammonemia in anorectic tumor-bearing rats

Plasma ammonia concentrations were significantly elevated by 150% in anorectic rats bearing methylcholanthrene sarcomas. Assessment of ammonia levels in blood draining these sarcomas indicated nearly a 20-fold increase as compared with venous blood in control rats, suggesting the tumor mass as the source of this increase in ammonia. Infusing increasing concentrations of ammonium salts produced anorexia and alterations in brain amino acids in normal rats that were similar to those observed in anorectic tumor-bearing rats. Therefore, these results suggest that ammonia released by tumor tissue may be an important factor in the etiology of cancer anorexia.     

Reduction of tumor growth following treatment with a glutamine antimetabolite

Assessment of arterial-venous differences across transplanted methylcholanthrene-induced sarcomas in rats revealed significant decreases in plasma concentrations of glutamine, serine and glucose. Treatment with the glutamine antimetabolite, acivicin, significantly reduced tumor weights by 65% at the conclusion of the experiment 34 days after tumor induction. These results suggest that glutamine is an essential metabolic substrate for tumor growth and that blockade of glutamine utilization can inhibit the growth of these transplantable sarcomas.     

The treatment of lower extremity sarcomas with wide excision, radiotherapy, and free-flap reconstruction.

Treatment of extremity sarcomas has evolved into a multidisciplinary approach utilizing surgery, radiotherapy, and, in some cases, chemotherapy. Limb-sparing surgery has maintained low rates of local recurrence when supplemented with early postoperative radiotherapy (brachytherapy). Leg defects that result from resection resemble those caused by trauma and appear ideally suited to free-flap reconstruction. However, the resection site is subjected to 4500 cGy of radiation given within 2 weeks of surgery. It has not been demonstrated that free flaps can endure early postoperative radiation without adverse effects. Three patients are presented with locally recurrent leg sarcomas treated by wide excision, brachytherapy, and free-flap reconstruction. All flaps survived, and the wounds healed uneventfully. This study reviews the current multidisciplinary approach to the treatment of lower extremity sarcomas and demonstrates the durability of free-flap reconstruction in the presence of early postoperative radiation therapy.     

MET Gene Copy Number Alterations and Expression of MET and Hepatocyte Growth Factor Are Potential Biomarkers in Angiosarcomas and Undifferentiated Pleomorphic Sarcomas

Soft tissue sarcomas are a heterogeneous group of tumors with many different subtypes. In 2014 an estimated 12,020 newly diagnosed cases and 4,740 soft tissue sarcoma related deaths can be expected in the United States. Many soft tissue sarcomas are associated with poor prognosis and therapeutic options are often limited. The evolution of precision medicine has not yet fully reached the clinical treatment of sarcomas since therapeutically tractable genetic changes have not been comprehensively studied so far. We analyzed a total of 484 adult-type malignant mesenchymal tumors by MET fluorescence in situ hybridization and MET and hepatocyte growth factor immunohistochemistry. Eleven different entities were included, among them the most common and clinically relevant subtypes and tumors with specific translocations or complex genetic changes. MET protein expression was observed in 2.6% of the cases, all of which were either undifferentiated pleomorphic sarcomas or angiosarcomas, showing positivity rates of 14% and 17%, respectively. 6% of the tumors showed hepatocyte growth factor overexpression, mainly seen in undifferentiated pleomorphic sarcomas and angiosarcomas, but also in clear cell sarcomas, malignant peripheral nerve sheath tumors, leiomyosarcomas and gastrointestinal stromal tumors. MET and hepatocyte growth factor overexpression were significantly correlated and may suggest an autocrine activation in these tumors. MET FISH amplification and copy number gain were present in 4% of the tumors (15/413). Two samples, both undifferentiated pleomorphic sarcomas, fulfilled the criteria for high level amplification of MET, one undifferentiated pleomorphic sarcoma reached an intermediate level copy number gain, and 12 samples of different subtypes were categorized as low level copy number gains for MET. Our findings indicate that angiosarcomas and undifferentiated pleomorphic sarcomas rather than other frequent adult-type sarcomas should be enrolled in screening programs for clinical trials with MET inhibitors. The screening methods should include both in situ hybridization and immunohistochemistry.     

Deletion mutations in the small t antigen gene alter the tissue specificity of tumors induced by simian virus 40.

Subcutaneous injection of wild-type simian virus 40 into Syrian hamsters normally induces fibrosarcomas at the injection site. We showed that subcutaneous injection of three different small t deletion mutants (dl884, dl883, and dl890) led to the formation of abdominal reticulum cell sarcomas (lymphomas) in about 15% of the animals bearing tumors. The remainder of the tumors were fibrosarcomas occurring with prolonged latencies at the site of injection. We postulated that, in the absence of an active small t protein, which is thought to have cell growth-promoting properties, the mutant virus preferentially transforms rapidly proliferating lymphoid cells.     

Characterization of Chemically Induced Ovarian Carcinomas in an Ethanol-Preferring Rat Model: Influence of Long-Term Melatonin Treatment

Ovarian cancer is the fourth most common cause of cancer deaths among women, and chronic alcoholism may exert co-carcinogenic effects. Because melatonin (mel) has oncostatic properties, we aimed to investigate and characterize the chemical induction of ovarian tumors in a model of ethanol-preferring rats and to verify the influence of mel treatment on the overall features of these tumors. After rats were selected to receive ethanol (EtOH), they were surgically injected with 100 µg of 7,12-dimethyl-benz[a]anthracene (DMBA) plus sesame oil directly under the left ovarian bursa. At 260 days old, half of the animals received i.p. injections of 200 µg mel/100 g b.w. for 60 days. Four experimental groups were established: Group C, rats bearing ovarian carcinomas (OC); Group C+EtOH, rats voluntarily consuming 10% (v/v) EtOH and bearing OC; Group C+M, rats bearing OC and receiving mel; and Group C+EtOH+M, rats with OC consuming EtOH and receiving mel. Estrous cycle and nutritional parameters were evaluated, and anatomopathological analyses of the ovarian tumors were conducted. The incidence of ovarian tumors was higher in EtOH drinking animals 120 days post-DMBA administration, and mel efficiently reduced the prevalence of some aggressive tumors. Although mel promoted high EtOH consumption, it was effective in synchronizing the estrous cycle and reducing ovarian tumor mass by 20%. While rats in the C group displayed cysts containing serous fluid, C+EtOH rats showed solid tumor masses. After mel treatment, the ovaries of these rats presented as soft and mobile tissues. EtOH consumption increased the incidence of serous papillary carcinomas and sarcomas but not clear cell carcinomas. In contrast, mel reduced the incidence of sarcomas, endometrioid carcinomas and cystic teratomas. Combination of DMBA with EtOH intake potentiated the incidence of OC with malignant histologic subtypes. We concluded that mel reduces ovarian masses and the incidence of adenocarcinomas in ethanol-deprived rats.     

Characteristics of the potential of the dorsal surface of the spinal cord in a chronic deficit of afferent influences

The changes of spinal cord dorsal potential (SCDP) has been studied on white rats to the posterior root stimulation at different intervals after sciatic nerve cutting. The increase of threshold, the decrease of amplitude, the growth of duration in some components of SCDP have been revealed on the site of the cutting. These changes were manifested at a less degree on the contralateral cutting site. A conclusion concerning the relative resistance of the spinal cord afferent system to the prolonged absence of peripheral afferent influence has been drawn.     

Evaluation of P-glycoprotein expression in soft tissue sarcomas of the extremities

Soft tissue sarcomas comprise a heterogeneous group of mesenchymal tumors accounting for less than one-percent of adult neoplasms. In the last few years, the use of adjuvant chemotorapy has been proposed for the treatment of these lesions in order to obain a better systemic control, but its usefulness is still controversial. In this study, we evaluated whether P-glycoprotein, a membrane protein strictly associated with multidrug resistance, is overexpressed in soft tissue sarcomas. By using human multidrug resistant sarcoma cell lines as controls, we analyzed P-glycoprotein expression in 34 primary and in 23 relapsed soft tissue sarcomas of the extremities. Overexpression of P-glycoprotein was found in 6 out of 34 primaries (18%) and in 8 out of 23 relapses (35%). In particular, in malignant fibrous histiocytoma, the most frequent soft tissue sarcoma of adults, P-glycoprotein overexpression was found in 23% of primary untreated cases, in agreement with the reported relapse rate of this tumor after surgery and chemotherapy. These data suggest that, in soft tissue sarcomas, overexpression of P-glycoprotein may be of prognostic value and that the assessment of P-glycoprotein expression may be useful for the design of chemotherapy protocols.Abbreviations MDR multidrug-resistance - STS soft tissue sarcomas     

Pazopanib in the Treatment of Bone Sarcomas: Clinical Experience

BACKGROUND: The effect of chemotherapy in metastatic bone sarcomas is poor and the condition is invariably fatal. Therefore, new treatment modalities are intensely needed. Pazopanib is a selective multitargeted tyrosine kinase inhibitor that has proven to be effective in the treatment of metastatic soft tissue sarcomas. The objective of this study was to evaluate the off-label use of pazopanib in patients with metastatic bone sarcomas who failed standard chemotherapy. METHODS: All patients with metastatic bone sarcomas treated with pazopanib between October 1st, 2011 and October 1st, 2017 at the Department of Oncology, Aarhus University Hospital were evaluated. Demographics, treatment, and survival outcomes were collected and analyzed. RESULTS: Nineteen patients were identified. The median age was 38 years (range 18–62). Most of the patients (50%) were diagnosed with osteosarcoma. All patients had documented disease progression at the time of initiating pazopanib treatment. The median overall survival was 11 months. Median progression free survival was 5.4 months. Out of 19 patients, 13 (68%) had either partial response or stable disease. In five patients, the dose of pazopanib was reduced because of toxicity. CONCLUSION: Off-label use of pazopanib is effective in the treatment of metastatic bone sarcomas of different histologies. Pazopanib was well tolerated in the treatment of patients with refractory bone sarcomas. Studies examining the effect of pazopanib alone or in combination with chemotherapy or other targeted therapies are needed.     

Induction of histiocytic sarcoma in mouse skeletal muscle

Myeloid sarcomas are extramedullary accumulations of immature myeloid cells that may present with or without evidence of pathologic involvement of the bone marrow or peripheral blood, and often coincide with or precede a diagnosis of acute myeloid leukemia (AML). A dearth of experimental models has hampered the study of myeloid sarcomas and led us to establish a new system in which tumor induction can be evaluated in an easily accessible non-hematopoietic tissue compartment. Using ex-vivo transduction of oncogenic Kras(G12V) into p16/p19(-/-) bone marrow cells, we generated transplantable leukemia-initiating cells that rapidly induced tumor formation in the skeletal muscle of immunocompromised NOD.SCID mice. In this model, murine histiocytic sarcomas, equivalent to human myeloid sarcomas, emerged at the injection site 30-50 days after cell implantation and consisted of tightly packed monotypic cells that were CD48+, CD47+ and Mac1+, with low or absent expression of other hematopoietic lineage markers. Tumor cells also infiltrated the bone marrow, spleen and other non-hematopoietic organs of tumor-bearing animals, leading to systemic illness (leukemia) within two weeks of tumor detection. P16/p19(-/-); Kras(G12V) myeloid sarcomas were multi-clonal, with dominant clones selected during secondary transplantation. The systemic leukemic phenotypes exhibited by histiocytic sarcoma-bearing mice were nearly identical to those of animals in which leukemia was introduced by intravenous transplantation of the same donor cells. Moreover, murine histiocytic sarcoma could be similarly induced by intramuscular injection of MLL-AF9 leukemia cells. This study establishes a novel, transplantable model of murine histiocytic/myeloid sarcoma that recapitulates the natural progression of these malignancies to systemic disease and indicates a cell autonomous leukemogenic mechanism.     

Soft tissue sarcoma in Italy: From epidemiological data to clinical networking to improve patient care and outcomes

Sarcomas are rare malignant neoplasms that develop from mesenchymal cells and include a heterogeneous and large group of histological subtypes that may occur at any anatomical site. Soft tissue sarcomas (STS), the focus of this review, account for ≈70‒80% of sarcomas and represent <1% of all cancers. The heterogeneity of STS applies to both their topography and morphology, and 5-year survival can vary widely depending on disease stage and the complex interplay between anatomical site and histology for different STS subtypes. The rarity and heterogeneity of STS, together with other factors, such as the lack of clinical expertise often lead to difficulties and delays in making an accurate diagnosis and to the inappropriate management of each STS subtype. Therefore, this group of cancers requires special attention and approaches to diagnosis and treatment. Epidemiological data on STS are limited, and concerns have been raised regarding accurate registration of STS in cancer registries, including issues related to details of the histotypes. This review provides an overview of the epidemiology of STS in Italy, focusing on data from the Italian Association of Cancer Registries (AIRTUM), and compares findings with those from other European countries. Based on these data, and considering that STS is among the most common group of rare cancers, the relevance of multidisciplinary care for STS patients through reference centres, clinical networks and collaborative disease-specific groups is discussed.     

Carcinogenic action of nickel and cadmium powders in the same rat

Powders of nickel and cadmium metals were compared for their relative carcinogenic action when injected in contra thigh muscles of legs in the same Fischer-344 rat. For negative controls, rats of both sexes were injected im with 0.2 mL of the suspending vehicle, trioctanoin, once a month for 12 m. The two positive controls were treated once a month with either a suspension of powdered nickel (10 mg/mL for 5 m) or powdered cadmium (5 mg/mL twice). These dose levels were those found previously in the authors' laboratories to yield fibrosarcomas in 50–70% of the treated animals. For the combined experiment where the animals were injected with Ni and Cd in contra legs, the doses were about one-half of that used for the positive controls. Individual vehicle controls were used for each group. The fibrosarcoma yields for the experiments with individual positive metal controls were: vehicle alone, 0%; for both nickel and cadmium injected individually, between 60 and 80% for both males and females. In the combined metal experiment, one male and one female vehicle control developed tumors at the site of injection. The yield in the nickel leg was 14% for the females and 57% for the males; in the cadmium leg, the values were 93 and 50%, respectively. Only one male and one female developed sarcomas in both legs; in each case, the cadmium-induced tumor appeared first and grew seven to eight times larger than that induced by nickel.     

Effect of age, castration and pregnancy on carcinogenesis, induced by 1,2-dimethylhydrazine, in CBA mice]

Subcutaneous injection of 1,2-dimethylhydrazine into female CBA mice once a week resulted in the development of tumours of the colon, anal region, uterus and liver. In 12-13-month-old mice treated with DMH an earlier appearance (week 8) of uterine sarcomas and more rapid increase in the incidence of tumours of the anal region were noted as compared to 3-month-old mice. In pregnant females treated with DMH a statistically significant decrease in the uterine sarcoma incidence was observed (10.3% versus 48.3% in nonpregnant). Pregnancy exerted no effect on the incidence of tumours at other sites. Castration did not affect the time of appearance and the incidence of tumours of any site.     

Relative biological effectiveness of 241Am relative to 192Ir for continuous low-dose-rate irradiation of BA1112 rat sarcomas

Sealed sources of 241Am have been developed for intracavitary irradiation of gynecological cancers. Relative to conventional isotopes (that is, 226Ra, 137Cs, 192Ir), 241Am allows for better shielding of dose-limiting normal tissues in the patient. In addition, the long half-life of 241Am (432 years) makes it an attractive isotope both for clinical use and for long-term radiobiology studies. Using a previously developed in vivo applicator system, BA1112 sarcomas on WAG/Rij Y rats were irradiated using 241Am or 192Ir at three different dose rates. Following in vivo treatment of the sarcomas with graded doses of radiation, cell survival curves were determined using an in vitro colony formation assay. The slopes of the resulting cell survival curves were observed to increase significantly as the dose rate increased from 0.30 to 0.60 Gy/h, then to decrease slightly as the dose rate increased from 0.60 to 0.95 Gy/h. The relative biological effectiveness (RBE) of 241Am relative to 192Ir was observed to increase linearly with increasing dose rate; the RBEs were 0.96 +/- 0.009, 1.09 +/- 0.12, and 1.17 +/- 0.11 at dose rates of 0.30, 0.60, and 0.95 Gy/h, respectively.     

Behavior and biological action of 239Pu administered intramuscularly during complexon therapy

With intramuscular injection of 239Pu nitrate the radionuclide content of the rat skeleton was higher, and at the site of injection, lower, than with injection of a polymer plutonium. The animals developed osteosarcomas (nitrate greater than polymer), and at the site of trauma, fibrosarcomas (nitrate less than polymer). After a complexon therapy the dose accretion in the skeleton and liver diminished, the life span increased, and the incidence of sarcomas decreased.     

Sequential quantitation of circulating immune complexes in syngeneic and allogeneic rats bearing Moloney sarcomas.

A Raji cell radioimmunoassay was employed to quantitate serially circulating immune complexes (CIC) in the sera of syngeneic BN rats and allogeneic Lewis rats bearing BN Moloney sarcomas. In syngeneic BN hosts the levels of CIC attained and the time-course of detection were related to the tumor dose, tumor mass, and regressive or progressive course of the tumor. In general, syngeneic rats that received larger tumor doses developed larger tumors and greater maximum levels of CIC. However, the amount of CIC was not always directly proportional to the tumor size, although this was nearly the case with regressor BN and Lewis rats. In rats with regressing tumors, CIC decreased to insignificant levels as the tumors disappeared. Progressor BN rats that received 20 and 10 X 10(6) tumor cells had higher and more sustained levels of CIC, but, shortly before the hosts died, despite an increase of tumor size, there was a decline of CIC. Progressor BN rats that received an initial inoculum of 0.5 X 10(6) tumor cells that grew to 44 mm maximum mean diameter had levels of CIC which were only slightly above levels of control rats. All allogeneic Lewis hosts rejected BN Moloney sarcomas, but had transient low levels of CIC coincident with tumor growth. Lewis rats had lower levels of CIC than BN rats bearing comparable masses of sarcoma.     

Comparison of spectral properties of 3-MC induced cytochrome P-448 from rabbits and rats.

EPR and optical spectral properties of cytochrome P-488 from 3-methylcholanthrene-induced rabbits are compared with those of rats. In the EPR spectra at 77K and in the optical absorption spectra at room temperature a considerable temperature independent high spin content of the rabbit cytochrome is observed which has been estimated to about 55% by titration with n-octylamine. On the other hand the high spin content of the rat cytochrome depends strongly on temperature and amounts to about 6% at 5 degrees C and to about 35% at 34 degrees C. The binding of substrates and ligands to the rabbit cytochrome as well as its reduction by sodium dithionite are slower as compared with the rat cytochrome but also with phenobarbital-induced cytochrome P-450 from rats and rabbits. Contrary to the 3-methylcholanthrene induced cytochrome P-448 from rats, that from rabbits does not bind 3-methylcholanthrene. A particular protein structure establishing the high spin state and an absent binding site for type I substrates is assumed to be responsible for these and other peculiarities of cytochrome P-448 from 3-methylcholanthrene-induced rabbits.     

Intermediate-sized filament proteins (keratin, vimentin, desmin) in metaplastic carcinomas, carcinosarcomas and stromal sarcomas of the breast

The distribution of intermediate-filament (IF) proteins of the keratin, vimentin and desmin type in breast stromal sarcomas, carcinosarcomas, metaplastic carcinomas and phyllodes tumors has been compared using the avidin-biotin complex immunoperoxidase technique. Keratin reactivity was found in carcinomatous and pseudosarcomatous areas of all metaplastic carcinomas, in the cuboidal epithelial cells of carcinosarcomas and in the epithelial component of phyllodes tumors. Vimentin and desmin were detected in the sarcomatous portion of carcinosarcoma, focally in the stromal component of phyllodes tumors and not always in the stromal sarcomas. These data confirm that combined analysis of IF expression is a reliable and convincing way to differentiate stromal sarcomas, metaplastic carcinomas and carcinosarcomas in breast pathology.     

Foetal amygdalar transplantation facilitates recovery of retention deficit in CeA lesioned rats

Neural tissue transplant has come off age as a valuable technique for studying normal development and regeneration. Bilateral lesions of the central nucleus of amygdala (CeA) produce complete retention and acquisition deficit in inhibitory avoidance paradigms. The present study reports recovery of retention deficit in active avoidance task (AA) after amygdalar tissue transplantation in CeA lesioned rats. In a group of adult wistar rats, bilateral lesions of the CeA were produced electrolytically. In a separate group of rats foetal amygdalar tissue was transplanted at the CeA lesioned site 2 days after producing lesion. All the rats were trained on AA task before and after 5 days of lesion. In bilaterally CeA lesioned rats, the percentage of avoidance (% avoidance) decreased significantly (P < 0.05) from 85 +/- 18% prelesion to 15.5 +/- 35% postlesion. However, no change in the % avoidance was observed after amygdalar tissue transplantation. The results indicate that the transplanted rats are capable of retaining the learnt information in contrast to the lesion alone group of rats.