Author Correction: Iscador Qu inhibits doxorubicin-induced senescence of MCF7 cells.

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A genome-wide Drosophila epithelial tumorigenesis screen identifies Tetraspanin 29Fb as an evolutionarily conserved suppressor of Ras-driven cancer.

Oncogenic mutations in the small GTPase Ras contribute to ~30% of human cancers. However, Ras mutations alone are insufficient for tumorigenesis, therefore it is paramount to identify cooperating cancer-relevant signaling pathways. We devised an in vivo near genome-wide, functional screen in Drosophila and discovered multiple novel, evolutionarily-conserved pathways controlling Ras-driven epithelial tumorigenesis. Human gene orthologs of the fly hits were significantly downregulated in thousands of primary tumors, revealing novel prognostic markers for human epithelial tumors. Of the top 100 candidate tumor suppressor genes, 80 were validated in secondary Drosophila assays, identifying many known cancer genes and multiple novel candidate genes that cooperate with Ras-driven tumorigenesis. Low expression of the confirmed hits significantly correlated with the KRASG12 mutation status and poor prognosis in pancreatic cancer. Among the novel top 80 candidate cancer genes, we mechanistically characterized the function of the top hit, the Tetraspanin family member Tsp29Fb, revealing that Tsp29Fb regulates EGFR signaling, epithelial architecture and restrains tumor growth and invasion. Our functional Drosophila screen uncovers multiple novel and evolutionarily conserved epithelial cancer genes, and experimentally confirmed Tsp29Fb as a key regulator of EGFR/Ras induced epithelial tumor growth and invasion.

Long-Term Culture of Distal Airway Epithelial Cells Allows Differentiation Towards Alveolar Epithelial Cells Suited for Influenza Virus Studies.

As the target organ for numerous pathogens, the lung epithelium exerts critical functions in health and disease. However, research in this area has been hampered by the quiescence of the alveolar epithelium under standard culture conditions. Here, we used human distal airway epithelial cells (DAECs) to generate alveolar epithelial cells. Long-term, robust growth of human DAECs was achieved using co-culture with feeder cells and supplementation with epidermal growth factor (EGF), Rho-associated protein kinase inhibitor Y27632, and the Notch pathway inhibitor dibenzazepine (DBZ). Removal of feeders and priming with DBZ and a cocktail of lung maturation factors prevented the spontaneous differentiation into airway club cells and instead induced differentiation to alveolar epithelial cells. We successfully transferred this approach to chicken distal airway cells, thus generating a zoonotic infection model that enables studies on influenza A virus replication. These cells are also amenable for gene knockdown using RNAi technology, indicating the suitability of the model for mechanistic studies into lung function and disease.

Iscador Qu inhibits doxorubicin-induced senescence of MCF7 cells.

Chemotherapy in patients with inoperable or advanced breast cancer inevitably results in low-dose exposure of tumor-cell subset and senescence. Metabolically active senescent cells secrete multiple tumor promoting factors making their elimination a therapeutic priority. Viscum album is one of the most widely used alternative anti-cancer medicines facilitating chemotherapy tolerance of breast cancer patients. The aim of this study was to model and investigate how Viscum album extracts execute additive anti-tumor activity with low-dose Dox using ER + MCF7 breast cancer cells. We report that cotreatment of MCF7 with Viscum album and Dox abrogates G2/M cycle arrest replacing senescence with intrinsic apoptotic program. Mechanistically, this switch was associated with down-regulation of p21, p53/p73 as well as Erk1/2 and p38 activation. Our findings, therefore, identify a novel mechanistic axis of additive antitumor activity of Viscum album and low dose-Dox. In conclusion, ER + breast cancer patients may benefit from addition of Viscum album to low-dose Dox chemotherapy due to suppression of cancer cell senescence and induction of apoptosis.

Sensitization of K562 Leukemia Cells to Doxorubicin by the Viscum album Extract.

Toxicity of conventional chemotherapeutics highlights the requirement for complementary or alternative medicines that would reduce side effects and improve their anticancer effectiveness. European mistletoe (Viscum album) has long been used as a complementary and alternative medicine supporting cancer therapy. The aim of this study was to investigate synergistic antitumor action of V. album extract and doxorubicin during co-treatment of chemoresistant chronic myelogenic leukemia K562 cells. Combined treatment of leukemia cells led to inhibitory synergism at sub-apoptotic doxorubicin concentrations and multifold reduction of cytotoxic effects in healthy control cells. Prolonged co-treatment was associated with reduced G2/M accumulation and increased expression of early and late apoptotic markers. Our data indicate that V. album extract increases antileukemic effectiveness of doxorubicin against resistant K562 cells by preventing G2/M arrest and inducing apoptosis.

Breast cancer in postmenopausal patients: Impact of age.

PURPOSE: We analyzed the significance of age together with other classic prognostic parameters on the course of breast cancer in postmenopausal patients. METHODS: Our study included 151 postmenopausal patients with primary breast cancer, of which 55% received adjuvant tamoxifen therapy and 45% did not receive any kind of therapy. Probabilities of disease-free interval (DFI) were estimated using the Kaplan-Meier method and were compared by the log-rank test. A p value<0.05 was considered as statistically significant. RESULTS: In the tamoxifen-treated subgroup, patients with estrogen receptor (ER) or progesterone receptor (PR) concentration≥5 fmol/mg had favorable course of disease (p<0.01, p<0.04), respectively. Patients≥66 years of age had a worse disease course compared to those<66 years. Also, patients≥66 years with pT1 tumors had a worse disease course compared to those<66 years and pT1 tumors. This result was repeated in other groups as well. In pT2 (≥2 cm), ER-positive, PR-positive and invasive ductal carcinoma (IDC) subgroups, patients≥66 years always had a worse disease course compared to patients<66 years. In the untreated subgroup, patients with ER≥52 fmol/mg (p<0.01), tumors≥2 cm (p<0.01), IDC (p<0.01) type or ≥56 years (p<0.04) had statistically more recurrences. Among patients≥56 years, those with ER-positive or pT2 tumors had shorter DFI compared to ER-negative or pT1. Positive correlation between ER, PR and age of patients was also shown in this subgroup (p<0.03, p<0.02). CONCLUSION: Age of patients, ER and PR are significant prognostic factors in the tamoxifen-treated subgroup. In the untreated subgroup relevant prognostic parameters are age, tumor size, histological type and ER. The above prognostic factors retained their value in the long-term follow up in both the investigated subgroups of patients.

Regulation of proliferation, cell competition, and cellular growth by the Drosophila JAK-STAT pathway.

The JAK-STAT pathway is a key regulator of tissue size in Drosophila melanogaster. Here we provide an overview of its roles in processes that regulate the size of Drosophila imaginal discs, epithelia of diploid cells that proliferate and acquire specific fates in the larvae and that become functional in the adult. Drosophila has a single JAK and a single STAT gene, which has facilitated genetic dissection of this pathway. Moreover, the sophisticated genetic tools available in flies for clonal growth assays have made Drosophila an ideal organism in which to dissect the multiple roles of the JAK-STAT pathway in growth control. Studies in flies have revealed JAK-STAT pathway activity as a central node for diverse signals that control proliferation and mass accumulation. In addition, recent work has establish a new role for the pathway in cell competition, a process thought to be akin to the early stages of transformation in which more robust cells kill and take the place of less robust ones.

Activated STAT regulates growth and induces competitive interactions independently of Myc, Yorkie, Wingless and ribosome biogenesis.

Cell competition is a conserved mechanism that regulates organ size and shares properties with the early stages of cancer. In Drosophila, wing cells with increased Myc or with optimum ribosome function become supercompetitors that kill their wild-type neighbors (called losers) up to several cell diameters away. Here, we report that modulating STAT activity levels regulates competitor status. Cells lacking STAT become losers that are killed by neighboring wild-type cells. By contrast, cells with hyper-activated STAT become supercompetitors that kill losers located at a distance in a manner that is dependent on hid but independent of Myc, Yorkie, Wingless signaling, and of ribosome biogenesis. These results indicate that STAT, Wingless and Myc are major parallel regulators of cell competition, which may converge on signals that non-autonomously kill losers. As hyper-activated STATs are causal to tumorigenesis and stem cell niche occupancy, our results have therapeutic implications for cancer and regenerative medicine.

A genome-wide Drosophila screen for heat nociception identifies α2δ3 as an evolutionarily conserved pain gene.

Worldwide, acute, and chronic pain affects 20% of the adult population and represents an enormous financial and emotional burden. Using genome-wide neuronal-specific RNAi knockdown in Drosophila, we report a global screen for an innate behavior and identify hundreds of genes implicated in heat nociception, including the α2δ family calcium channel subunit straightjacket (stj). Mice mutant for the stj ortholog CACNA2D3 (α2δ3) also exhibit impaired behavioral heat pain sensitivity. In addition, in humans, α2δ3 SNP variants associate with reduced sensitivity to acute noxious heat and chronic back pain. Functional imaging in α2δ3 mutant mice revealed impaired transmission of thermal pain-evoked signals from the thalamus to higher-order pain centers. Intriguingly, in α2δ3 mutant mice, thermal pain and tactile stimulation triggered strong cross-activation, or synesthesia, of brain regions involved in vision, olfaction, and hearing.

Genome-wide RNAi screen identifies genes involved in intestinal pathogenic bacterial infection.

Innate immunity represents the first line of defense in animals. We report a genome-wide in vivo Drosophila RNA interference screen to uncover genes involved in susceptibility or resistance to intestinal infection with the bacterium Serratia marcescens. We first employed whole-organism gene suppression, followed by tissue-specific silencing in gut epithelium or hemocytes to identify several hundred genes involved in intestinal antibacterial immunity. Among the pathways identified, we showed that the JAK-STAT signaling pathway controls host defense in the gut by regulating stem cell proliferation and thus epithelial cell homeostasis. Therefore, we revealed multiple genes involved in antibacterial defense and the regulation of innate immunity.

Severe central nervous system thrombotic events in hemoglobin Sabine patient.

Hemoglobin (Hb) Sabine is a rare, unstable Hb variant resulting from the point mutation in codon 91 (CTG --> CCG) of beta-globin gene. We report a case of Hb Sabine patient with mild hemolytic anemia, unusually high Hb F level and severe central nervous system thrombotic disturbances. We have tried to elucidate possible genetic background of this unusual Hb Sabine phenotype. Extremely high level of Hb F and rather mild anemia in our patient could be partially explained by the presence of G gamma Xmn I polymorphism. This case of Hb Sabine, unlike all other reported to date, shows extremely severe thromboembolic complications. It is our opinion that the hypercoagulable state described in thalassemia is not the only factor responsible for this specific clinical state. The presence of MTHFR C677T mutation in heterozygous state found in our patient and unstable Hb Sabine molecules could contribute to development of thromboembolic phenomena. However, it remains unclear whether other factors participate in pathogenesis of the disease. In this paper we emphasize different genetic background of father and son both affected with Hb Sabine, but with markedly different severity of the disease.