Gastric carcinoma and renal cell carcinoma as an atypical presentation of multiple primary malignancies: a case report and review of the literature.

BACKGROUND: Gastric carcinoma (GC) with second primary malignancy (SPM) is the most frequent combination within the multiple primary malignancies (MPM) group. The presentation of a GC associated with a synchronized SPM in the kidney is extremely rare and unusual. This study presents a rare case of synchronous tumors, describes the main associated risk factors, and emphasizes the need to rule out SPM. MAIN BODY: We present the case of a 63-year-old Hispanic woman with a history of smoking, weight loss, and gastrointestinal (GI) bleeding. GC was diagnosed by endoscopy, and during her workup for metastatic disease, a synchronous SPM was noted in the left kidney. The patient underwent resection of both tumors with a satisfactory postoperative course. A systematic review of the literature was performed using the Medline/PubMed, Science Direct, Scopus, and Google Scholar databases. A search of the literature yielded 13 relevant articles, in which the following main risk factors were reported: the treatment utilized, the grade and clinical stage, histopathological report, and in some cases survival. It is concluded that advanced age (> 60 years) and smoking are the main associated risk factors. CONCLUSION: Gastric carcinoma is the second most frequent neoplasm of the GI tract and the main neoplasm that presents a SPM. MPM screening is recommended in patients with gastric cancer. The clinical discovery of MPM of renal origin is rare and hence the importance of the current report.

Transformation by Rous sarcoma virus induces clathrin heavy chain phosphorylation.

We have shown that the heavy chain of clathrin is phosphorylated in chicken embryo fibroblast cells transformed by Rous sarcoma virus, but not in normal cells. Approximately 1 mol of phosphate is bound for every 5 mol of heavy chain in the maximally phosphorylated transformed cells. Two-thirds of the phosphate is on serine and one-third on tyrosine residues. Clathrin heavy chain is a substrate for pp60v-src in vitro. Cleveland analysis of the in vivo and in vitro clathrin heavy chain phosphopeptides, generated by protease V8 digestion, show labeled proteolytic fragments of similar molecular weight, suggesting that pp60v-src could be directly responsible for the in vivo phosphorylation of clathrin. Phosphate is equally incorporated into clathrin in both the unassembled and the assembled clathrin pools, whereas [35S]methionine is preferentially incorporated into the assembled pool. In normal cells, clathrin visualized by immunofluorescent staining appears in a punctate pattern along the membrane surface and concentrated around the nucleus; in transformed cells the perinuclear staining is completely absent. The phosphorylation of clathrin heavy chain in transformed cells may be linked to previously observed transformation-dependent alterations in receptor-mediated endocytosis of ligands such as EGF and thrombin.

Inhibitory action of a met-enkephalin on ACTH release in man.

In order to study the mechanism of action of a Met-enkephalin (FK 33824) on the pituitary-adrenal axis eight normal male volunteers were subjected to an ACTH stimulation test. Lysine-vasopressing (LVP), 5 IU, was injected intramuscularly after pretreatment with 0.5 mg FK 33824 i.m. or a placebo. In six of the subjects the opiate was again administered preceding a single injection of 0.25 mg ACTH beta 1-24 i.m. Blood was collected at regular intervals and ACTH and cortisol concentrations analyzed in all samples. LVP induced significant plasma ACTH (P < 0.05) and cortisol (P < 0.001) increases. Pretreatment with FK 33824 completely antagonized the effect of LVP. Furthermore, the cortisol elevation after exogenous ACTH was not modified by previous administration of FK 33824. It is concluded that the Met-enkephalin derivative FK 33824 directly suppresses ACTH release from the pituitary without influencing adrenal synthesis of cortisol.

Attenuation of ribosomal protein S6 phosphatase activity in chicken embryo fibroblasts transformed by Rous sarcoma virus.

In chicken embryo fibroblasts, phosphorylation of the 40S ribosomal protein S6 increases during G1 but returns to basal level by mitosis. In contrast, in Rous sarcoma virus (RSV)-transformed fibroblasts, S6 remains highly phosphorylated throughout mitosis. This study investigated the mechanism by which RSV alters the pattern of S6 phosphorylation. Pulse-chase experiments demonstrate that phosphate turnover in S6 is rapid in normal cells and in cells infected with an RSV transformation-defective virus. In contrast, phosphate turnover in S6 is severely reduced in cells infected with temperature-sensitive RSV at a temperature permissive for transformation, indicating a diminished S6 phosphatase activity. Fractionation of cell lysates by DEAE chromatography showed an almost threefold lower S6 phosphatase activity in RSV-transformed versus normal cells. The S6 phosphatase was sensitive to inhibitor 2 and specifically recognized by an antibody to type 1 phosphatase (PP1). The S6 phosphatase activity recovered by immunoprecipitation of PP1 was threefold lower in transformed cells, but the steady-state level of expression and the rate of synthesis of PP1 were not altered by oncogenic transformation. Together, the results show that transformation by RSV reduced the S6-PP1 activity.

Src family kinases are required for prolactin induction of cell proliferation.

Prolactin (PRL) is a pleiotropic cytokine promoting cellular proliferation and differentiation. Because PRL activates the Src family of tyrosine kinases (SFK), we have studied the role of these kinases in PRL cell proliferation signaling. PRL induced [(3)H]thymidine incorporation upon transient transfection of BaF-3 cells with the PRL receptor. This effect was inhibited by cotransfection with the dominant negative mutant of c-Src (K>A295/Y>F527, SrcDM). The role of SFK in PRL-induced proliferation was confirmed in the BaF-3 PRL receptor-stable transfectant, W53 cells, where PRL induced Fyn and Lyn activation. The SFK-selective inhibitors PP1/PP2 and herbimycin A blocked PRL-dependent cell proliferation by arresting the W53 cells in G1, with no evident apoptosis. In parallel, PP1/PP2 inhibited PRL induction of cell growth-related genes c-fos, c-jun, c-myc, and odc. These inhibitors have no effect on PRL-mediated activation of Ras/Mapk and Jak/Start pathways. In contrast, they inhibited the PRL-dependent stimulation of the SFKs substrate Sam68, the phosphorylation of the tyrosine phosphatase Shp2, and the PI3K-dependent Akt and p70S6k serine kinases. Consistently, transient expression of SrcDM in W53 cells also blocked PRL activation of Akt. These results demonstrate that activation of SFKs is required for cell proliferation induced by PRL.

An Update on Src Family of Nonreceptor Tyrosine Kinases Biology.

The members of the Src family of nonreceptor tyrosine kinases (SFKs) are implicated in multiple signaling processes that regulate key cellular functions, including proliferation, migration, differentiation, and survival. SFKs are activated by a large number of receptors for growth factors, cytokines, steroid hormones, G protein-coupled receptors, and also by adhesion proteins and other signaling partners. Through their common modular kinase an adapter protein domains, SFKs critically contribute to diversify different signal inputs, weaving a complex and dynamic network of cellular responses. Not surprisingly, SFKs are involved in embryo development and in the maintenance of different adult tissues and organs. Conversely, dysfunction of SFKs is associated with different pathologies, including cancer. Despite the continuous research in the field, several aspects of SFKs regulation and function are still not well defined and new roles for these proteins are steadily reported. The aim of this review is to provide an update on the major regulatory mechanisms of SFKs activity, including the emerging redox-dependent pathway. We have also focused on the functional implications of SFKs in Prolactin signaling and breast cancer development, two increasingly important aspects of SFKs biology. Finally, we briefly revisited the role of SFKs during embryo development and provide insights on the involvement of these proteins in the regulation of embryonic, somatic, and breast cancer stem cells.

Atmospheric deposition of 137Cs between 1994 and 2002 at Cienfuegos, Cuba.

Levels of 137Cs in total atmospheric deposition have been measured in the Cienfuegos region (Cuba) between 1994 and 2002. Samples were collected every three months, evaporated to dryness to obtain residual samples, and measured by gamma spectrometry. The 137Cs mean concentration in total deposition was 0.24 Bq m(-2) and data ranged between < 0.05 and 0.62 Bq m(-2). Precipitation rates and raintime have proved to be the most important factors controlling the concentration and depositional flux of 137Cs in the atmosphere over Cienfuegos, showing a high correlation coefficient (R = 0.93).

Prolactin receptor is associated with c-src kinase in rat liver.

The mechanism of action of the pituitary hormone PRL was studied in hepatocytes of lactating rats. PRL receptor immune complexes obtained from liver lysates have an associated tyrosine kinase activity. The tyrosine kinase has been identified in isolated hepatocytes as pp60c-src. Incubation of hepatocytes with PRL induces the association of PRL receptor with pp60c-src and the resultant stimulation of its tyrosine kinase activity. Furthermore, PRL stimulates the gene expression of c-fos, c-jun, and c-src. All of these findings support the idea that the pp60c-src tyrosine kinase participates in the early steps of the PRL intracellular signaling that promotes cell growth in liver cells.

Usefulness of Clinical Signs and Diagnostic Tests for Suspected Leaks in Bariatric Surgery.

BACKGROUND: The early diagnosis of leakage poses a challenge to bariatric surgeons, who need to suspect and treat it promptly. The aim of this study is to determine the value of clinical signs and complementary tests in its detection. METHODS: Between January 2007 and 2012, 200 patients underwent surgery for pathological obesity. Perioperative variables were collected prospectively, and univariate and multivariate analyses were conducted to study the factors related to leak occurrence and the predictive value of the tests performed. RESULTS: The study includes 172 proximal gastric bypasses and 28 sleeve gastrectomies. Nine patients (4.5 %) had leaks in the immediate postoperative period. Multivariate analyses found that age over 48 years and preoperative BMI > 48 kg/m(2) were the patient-related variables associated with a higher risk of leakage. The clinical variables significantly related to postoperative leaks were heart rate over 100 bpm, leukocytes over 15,000/mm(3) and systolic arterial pressure below 100 mmHg. In patients with a clinical suspicion of leakage (n = 19), 7.7 % of abdominal CT scans returned false negatives, versus 28.6 % for oral methylene blue and 22.2 % for upper gastrointestinal (UGI) Gastrografin swallow [Corrected]. CONCLUSIONS: Bariatric surgery proved to be a safe technique at our medical centre. Patient-related variables associated with a higher risk of leakage were age and BMI. Early clinical signs of leakage were tachycardia, leukocytosis and hypotension. The most reliable diagnostic test was the abdominal CT scan.

Ha-ras interference with thyroid cell differentiation is associated with a down-regulation of thyroid transcription factor-1 phosphorylation.

Mechanisms responsible for the lack of thyroid-specific differentiation markers in Ha-ras transformed FRTL-5 cells have been investigated. In vivo cell labeling and immunoprecipitation demonstrate that phosphorylation of the thyroid transcription factor-1 (TTF-1) is clearly reduced in thyroid cells transformed with the Ha-ras oncogene. Fingerprinting analysis of phosphotryptic peptides from FRTL-5 and Ha-ras-FRTL-5 cells also reveals a heterogeneous pattern of TTF-1 phosphorylation in the transformed cell line. This heterogeneity is localized in the amino terminal cluster of phosphoserines, as determined by transfection of HeLa cells with TTF-1 mutants in which serine residues have been replaced by alanines. Amplification and nucleotide sequence of the 5'-coding region of the TTF-1 gene in Ha-ras-FRTL-5 cells rule out the possibility that differences in phosphorylation were the consequence of any mutational event affecting residues within the N-terminal protein sequence. Hypophosphorylated TTF-1 is still able to bind its DNA consensus sequence within the thyroglobulin promoter, although a reporter construct whose expression is exclusively dependent on TTF-1 is not transactivated. Transfection of Ha-ras-FRTL-5 cells with an expression vector encoding the cAMP dependent protein kinase A (PKA) catalytic subunit partially reestablishes TTF-1 transcriptional activity. Taken together, these results indicate that the lack of specific thyroid gene expression in Ha-ras-FRTL-5 cells could be a direct consequence of the inability of TTF-1 to promote transcription.

MYC antagonizes the differentiation induced by imatinib in chronic myeloid leukemia cells through downregulation of p27(KIP1.).

Chronic myeloid leukemia (CML) progresses from a chronic to a blastic phase where the leukemic cells are proliferative and undifferentiated. The CML is nowadays successfully treated with BCR-ABL kinase inhibitors as imatinib and dasatinib. In the CML-derived K562 cell line, low concentrations of imatinib induce proliferative arrest and erythroid differentiation. We found that imatinib upregulated the cell cycle inhibitor p27(KIP1) (p27) in a time- and -concentration dependent manner, and that the extent of imatinib-mediated differentiation was severely decreased in cells with depleted p27. MYC (c-Myc) is a transcription factor frequently deregulated in human cancer. MYC is overexpressed in untreated CML and is associated to poor response to imatinib. Using K562 sublines with conditional MYC expression (induced by Zn(2+) or activated by 4-hydroxy-tamoxifen) we show that MYC prevented the erythroid differentiation induced by imatinib and dasatinib. The differentiation inhibition is not due to increased proliferation of MYC-expressing clones or enhanced apoptosis of differentiated cells. As p27 overexpression is reported to induce erythroid differentiation in K562, we explored the effect of MYC on imatinib-dependent induction of p27. We show that MYC abrogated the imatinib-induced upregulation of p27 concomitantly with the differentiation inhibition, suggesting that MYC inhibits differentiation by antagonizing the imatinib-mediated upregulation of p27. This effect occurs mainly by p27 protein destabilization. This was in part due to MYC-dependent induction of SKP2, a component of the ubiquitin ligase complex that targets p27 for degradation. The results suggest that, although MYC deregulation does not directly confer resistance to imatinib, it might be a factor that contributes to progression of CML through the inhibition of differentiation.

Protein tyrosine phosphatase 1B modulates GSK3ß/Nrf2 and IGFIR signaling pathways in acetaminophen-induced hepatotoxicity.

Acute hepatic failure secondary to acetaminophen (APAP) poisoning is associated with high mortality. Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of tyrosine kinase growth factor signaling. In the liver, this pathway confers protection against injury. However, the involvement of PTP1B in the intracellular networks activated by APAP is unknown. We have assessed PTP1B expression in APAP-induced liver failure in humans and its role in the molecular mechanisms that regulate the balance between cell death and survival in human and mouse hepatocytes, as well as in a mouse model of APAP-induced hepatotoxicity. PTP1B expression was increased in human liver tissue removed during liver transplant from patients for APAP overdose. PTP1B was upregulated by APAP in primary human and mouse hepatocytes together with the activation of c-jun (NH2) terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK), resulting in cell death. Conversely, Akt phosphorylation and the antiapoptotic Bcl2 family members BclxL and Mcl1 were decreased. PTP1B deficiency in mouse protects hepatocytes against APAP-induced cell death, preventing glutathione depletion, reactive oxygen species (ROS) generation and activation of JNK and p38 MAPK. APAP-treated PTP1B(-/-) hepatocytes showed enhanced antioxidant defense through the glycogen synthase kinase 3 (GSK3)ß/Src kinase family (SKF) axis, delaying tyrosine phosphorylation of the transcription factor nuclear factor-erythroid 2-related factor (Nrf2) and its nuclear exclusion, ubiquitination and degradation. Insulin-like growth factor-I receptor-mediated signaling decreased in APAP-treated wild-type hepatocytes, but was maintained in PTP1B(-/-) cells or in wild-type hepatocytes with reduced PTP1B levels by RNA interference. Likewise, both signaling cascades were modulated in mice, resulting in less severe APAP hepatotoxicity in PTP1B(-/-) mice. Our results demonstrated that PTP1B is a central player of the mechanisms triggered by APAP in hepatotoxicity, suggesting a novel therapeutic target against APAP-induced liver failure.

Vertical distribution and inventories of (239+240)Pu and mercury in Sagua la Grande estuary, Cuba.

The vertical activity distribution and inventories of (239+240)Pu profile and Hg were determined in Sagua la Grande estuary, Cuba. The shape of the (239+240)Pu profile in the core column resembled very closely the history of atmospheric nuclear weapons' testing, and the maximum deposition in 1963 was recorded in the sediment core history. The (239+240)Pu activity concentrations in the surface layer sediments varied from 0.163 to 0.611 mBq g(-1). The inventory of (239+240)Pu was 42 ± 5.6 Bq m(-2), a value close to that expected from direct global fallout. Using the (239+240)Pu as a chronomarker the mass sedimentation rate in the area for the last 60 years was calculated, reaching values of 0.173 g cm(-2) y(-1). The mercury profile reflects the history of anthropogenic pollution in the estuary and perfectly describes the operation of the mercury-cell chlor-alkali plant, for production of NaOH, which began operations in 1980. The inventory of Hg was 2.42 ± 0.19 µg cm(-2). These results contribute to the scarce regional database for pollutants and anthropogenic radionuclides in the Caribbean marine environment, particularly in relation to (239+240)Pu.

Activation of the unliganded estrogen receptor by prolactin in breast cancer cells.

Both prolactin (PRL) and estrogen (E2) are involved in the pathogenesis and progression of mammary neoplasia, but the mechanisms by which these hormones interact to exert their effects in breast cancer cells are not well understood. We show here that PRL is able to activate the unliganded estrogen receptor (ER). In breast cancer cells, PRL activates a reporter plasmid containing estrogen response elements (EREs) and induces the ER target gene pS2. These actions are blocked by the antagonist ICI 182,780, showing that ER is required for the PRL-mediated effect. Moreover, PRL leads to phosphorylation of ERalpha in serine-118 (P-ERalpha), a modification related to the potentiation of ligand-independent transcriptional activation. In addition, PRL mimics the effect of E2 on target gene expression by inducing cyclical recruitment of ERalpha and P-ERalpha to ERE-containing promoters, resulting in recruitment of co-activators and acetylation of histone H3. Finally, PRL induces expression of c-Myc and Cyclin D1 and leads to increased cell proliferation, which is specifically antagonized by ICI 182,780 or ERalpha depletion. These results show that ligand-independent ERalpha activation appears to be an important component of the proliferative and transcriptional actions of PRL in breast cancer cells.

Effect of dopamine receptor stimulation on the inhibition of LH pulsatility by a met-enkephaline (FK 33-824).

Plasma LH fluctuations reflect pulsatile hypothalamic GnRH activity. In order to investigate a possible interaction between opiate and dopaminergic pathways in the control of LH and PRL release, a met-enkephalin analogue (FK 33-824) was administered intravenously to female volunteers at a rate of 0.01 mg/kg/h for 4 h. LH pulses as recorded by plasma measurements every 20' were significantly (p less than 0.01) inhibited whereas PRL concentrations were increased. Pre-treatment with bromocriptine, 1.25 mg b.i.d. for 3 days, counteracted the stimulatory effect of FK 33-824 on PRL secretion but the inhibitory effect on LH episodic release was not modified by this dopamine agonist. Results indicate that opiate receptor stimulation selectively depresses hypothalamic GnRH activity and enhances PRL release from pituitary lactotrops. The GnRH lowering effect does not seem to be mediated by dopaminergic mechanisms which govern PRL secretion. Also transient, opioid-induced hyperprolactinemia is not causally related to the suppression of hypothalamic GnRH activity.

Ordered phosphorylation of 40S ribosomal protein S6 after serum stimulation of quiescent 3T3 cells.

The amino acids and tryptic peptides that become phosphorylated in 40S ribosomal protein S6 after serum stimulation of quiescent 3T3 cells were examined by two-dimensional thin-layer electrophoresis. In the maximally phosphorylated form of the protein, most of the phosphate was incorporated into serine and a small amount, into threonine. Digestion of this form of the protein with trypsin revealed 10 major phosphopeptides. All 10 contained phosphoserine and 2 of the 10 also contained phosphothreonine. Next, the five forms of increasingly phosphorylated S6 were individually separated on two-dimensional polyacrylamide gels or total S6 was isolated from cells that were stimulated for only a short time and their phosphotryptic maps were analyzed. The results showed that, as larger amounts of phosphate were added to S6, the phosphopeptides appeared in a specific order.

Phosphorylation of the human-transforming-growth-factor-beta-binding protein endoglin.

Endoglin is an homodimeric membrane antigen with capacity to bind transforming growth factor-beta (TGF-beta). Phosphorylation of human endoglin was demonstrated in endothelial cells as well as in mouse fibroblast transfectants expressing two isoforms, L-endoglin or S-endoglin, with distinct cytoplasmic domains. The extent of L-endoglin phosphorylation was found to be 8-fold higher than that of S-endoglin, and phosphopeptide analyses revealed at least three different phosphorylation sites for L-endoglin, whereas S-endoglin produces only one phosphopeptide. The immunoprecipitated L-endoglin was found to be phosphorylated mainly on serine, and, to a minor extent, on threonine, residues. Treatment of the cells with TGF-beta 1 or the protein kinase C inhibitor H-7 resulted in a reduction of the levels of endoglin phosphorylation.