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Background: Persistent activation of PI3K-AKT signaling and its regulated mTOR axis promote cell growth and proliferation in a variety of tumor types including breast tumors. A strong association has been demonstrated between mutational activation of PIK3CA or loss of function of PTEN, and resistance to therapies targeted against the ER or HER2 pathway. Purpose: Since PI3K-AKT-mTOR is one of the major signaling pathways responsible for the progression of breast cancer, and appears to be upregulated during development of the resistance to the endocrine and trastuzumab treatment, suppression of this pathway by administration of GDC0941 (PI3K inhibitor) may therefore be efficacious in ER+ and HER2+ breast cancer models. Experimental Design: GDC0941 was treated in ER+ (MCF7, HCC1500, BT483, T47D and MDA-MB-415), HER2+/ trastuzumab (T)-sensitive (BT474), T-resistant (BT474HR), and PIK3CA mutated/HER2+ breast cancer cells (HCC1954 and UACC893). We tested the effects of GDC0941 on the (a) cell survival/proliferation, (b) integrin-directed cell migration, (c) downstream signaling pathways for proliferation and apoptosis, and (d) hypoxia-induced HIF1α accumulation. Results: Treatment of GDC0941 in ER+ and HER2+ cell lines in vitro showed that 1) cell lines were sensitive to single agent GDC0941 with IC50 ranging from 0.3 μM to 2.5 μM in ER+ cell lines and 0.35 μM to1.0 μM in HER2+ cell lines, 2) GDC0941 dose- and time-dependently blocked downstream effectors of the PI3K-AKT pathway i.e. p-AKT (at Ser473, Thr 308), p-P70S6K, p-S6 ribosomal protein, and p-4EBP1(although in lesser extent) in all cell lines, 3) inhibition of AKT was more pronounced when T was combined with GDC0941 even at lower concentrations in both T-sensitive and T-resistant cells, 4) activation of ERK occurred in ER+/PIK3CA helical domain mutated, ER+PTEN-mutated cells, and HER2+/T-resistant cells, 5) in HER2+ cell lines, GDC0941treatment resulted in induction of apoptosis via cleavage of CASPASE3 in a dose-and time-dependent manner, 6) GDC0941 significantly abrogated hypoxia-induced HIF1α stabilization in ER+ and HER2+ cells. Interestingly, in GDC0941 treated cells, MG132 (proteosome inhibitor) restored the inhibitory effect of GDC0941 on HIF1α protein levels in hypoxic conditions, and 7) integrin-dependent cell migration was significantly abrogated with GDC0941 in ER+ and HER2+ (both in T-sensitive and T-resistant) cells. Conclusion: Our preclinical in vitro data demonstrate that GDC0941 inhibits cell proliferation and PI3K signaling in both ER+ and HER2+ breast cancer cells. A combination therapy with anti-estrogen+PI3K inhibitor and anti-HER2 agent+PI3K inhibitor significantly inhibits ER+ cell proliferation (including PIK3CA or PTEN mutated cells) and reverses HER2 resistance in our model systems. Citation Format: Pradip KR De, Yuliang Sun, Lori Friedman, Nandini Dey, Brian Leyland-Jones. In vitro potency of pan-inhibitor of class 1 PI3K, GDC0941 in ER+ and HER2 overexpressing breast cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 545. doi:10.1158/1538-7445.AM2013-545

Background: PARP is a promising target in the Triple Negative subset of Breast Cancer, the most aggressive subset characterized by poor prognosis and limited option for targeted therapy. The PI3K pathway, in addition to its pro-proliferative effects on tumor cells, also contributes to the repair of DSB in both a kinase-dependent and independent manner (Kumar, 2010) directly by controlling relevant enzymes (Friedman, 2009) or indirectly by regulating the expression of repair-related proteins. PI3K inhibition impairs BRCA1/2 expression in BRCA-proficient cells leading to the DNA damage, and HR impairment (Juvekar, 2012; Ibrahim, 2012). Purpose: We hypothesize that an additional inhibition of HR and NHEJ by GDC-0980 in conjunction with the inhibition of classical PI3K-mTOR survival signals, will induce more effective anti-proliferative and pro-apoptotic signals in BRCA-competent TNBC cells when combined with PARP inhibitor (impaired DNA-SSB-repair), and carboplatin (increased DNA-DSB). Methods: We tested effects of ABT888, and GDC-0980 (alone, and combination), on cell survival/ proliferation in a panel of 5-7 BRCA-wt and mutant TNBC cell lines using MTT assay, CelltiterGLO, and cell cycle analyses (PI & EDU). Clonogenic growth was tested by 3D ON-TOP assay and soft-agar assay. Apoptosis (Annexin V, Apoptosis Array), and cell signaling marker(s) (WB) were investigated. Results: The results show that, (1) the range of EC50s for GDC-0980 in cells (HCC70, HCC1143, HCC1937, MDA-MB231, MDA468, BT20) varied from 0.2 μM to 5 μM; PIK3CA mutated (H1047R) BT20 cells exhibited the lowest EC50, while RAS/RAF mutated MDA-MB231 cells exhibited the highest EC50, (2) PTEN-null and ATM kinase mutated MDA-MB468 cells were the most sensitive to ABT888 in the dose-response study by clonogenic assay (ABT888 failed to show a response by MTT assay), (3) out of three doses of GDC-0980 (200 nM, 100 nM, and 50 nM) tested in combination with ABT888 (10μM) plus carboplatin (10 μM), BRCA-competent MDA-MB468 cells were found to be more sensitive to the combination at 50 nM GDC-0980 than BRCA-competent MDA-MB231 cells, (4) GDC-0980 treatment (50nM) decreased pAKT-S473 and pP70S6K, and (5) GDC-0980 treatment time-dependently increased cleaved-caspase 3, 9, and cleaved-PARP in cells. Conclusion: Data indicate that GDC-0980 enhances the activity of ABT888, in the presence of carboplatin. We are currently pursuing the studies to delineate the mechanistic relationship between the anti-proliferative, pro-apoptotic, and anti-DNA-damage-repair effects of GDC-0980 in BRCA-competent TNBC cell lines in combination with ABT888 plus carboplatin, the results of which will be presented in the meeting. Citation Format: Nandini Dey, Jennifer Carlson, Yuliang Sun, Lori Friedman, Pradip De, Brian Leyland-Jones. Dual PI3K/mTOR inhibitor, GDC-0980 sensitizes BRCA-competent triple negative breast cancer cells to ABT888 in the presence of carboplatin by impairing DNA-damage repair: A proof of concept combination of PI3K/mTOR inhibitor with PARP inhibitor . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 544. doi:10.1158/1538-7445.AM2013-544

e13579 Background: BRCA1-deficiency confers sensitivity to PARP1 inhibition (alone or in combination with platinum compounds) in triple-negative breast cancer (TNBC). Recent understanding of the biology of TNBC tumor cells has recognized molecular targets suitable for treatment with targeted therapeutics including cell surface RTK(s), such as EGFR. Methods: We studied the effect of combination of PARP inhibitor, (olaparib) plus carboplatin with a dual EGFR/VEGFR inhibitor, vandetanib in a TNBC model in both in vitro and in vivo settings. We tested the effects of drug combinations on (a) cell signaling marker(s) of survival/proliferation/apoptosis, (b) adhesion-dependent and clonogenic survival, and (c) different phenotypes (migration, invasion, vascular mimicry, and cord formation) using TNBC cell and HUVEC cells. The combination of PARP1 inhibition and EGFR/VEGFR inhibition was evaluated in tumor-bearing athymic mice treated with olaparib plus carboplatin and vandetanib. Results: Data showed that, (1) EC50s for vandetanib ranged from 5-15 µM, (2) vandetanib (10 µM) inhibited phosphorylation of AKT (S473 & T308), S6RP, 4EBP1 and ERK, (3) effect of olaparib on TNBC cell survival can be effectively studied in vitro by clonogenic assay, (4) TNBC cell lines exhibited higher sensitivity to vandetanib in clonogenic assay when combined with 10 µM fixed dose of olaparib, and (5) a combination of vandetanib with olaparib plus carboplatin time dependently increased caspase-3 and PARP cleavage, inhibited vascular mimicry, blocked fibronectin-directed migration, and suppressed clonogenic growth in TNBC cells.Vandetanib blocked (a) cord formation, (b) vitronectin-directed migration, and (c) HIF-1alpha accumulation and phosphorylation of proliferation markers (AKT, 4EBP1, and ERK) in HUVEC cells. Conclusions: Anti-proliferative/pro-apoptotic, and anti-migratory/invasive effects of vandetanib (alone or in combination with carboplatin plus olaparib) were observed both in tumor cells and in endothelial cells. We are currently studying in vivo the effect of combining olaparib plus carboplatin with vandetanib, in xenograft model the results of which will be presented in the meeting.

Background: Members of the phosphatidylinositiol 3-kinase (PI3K) pathway are frequently upregulated/amplified in broad range of cancers including breast cancer. The PIK3CA mutation or the loss-of-function of PTEN, which are found in different subsets of breast cancer, activates the PI3K-AKT-mTOR pathway, resulting in breast cancer development, progression and lower clinical benefit rate. Purpose: We investigated the comparison of inhibitory potency of p110α-specific inhibitor (INK1402) versus PI3K/mTOR dual inhibitor (BEZ235) in PI3K activated (define as activating mutation of PIK3CA or by loss-of-function of PTEN) hormone receptor positive (HR+) and triple negative (TN) breast tumor cells (a proof-of-concept study). Experimental Design: We used HR+ (MCF7, T47D and MDA-MB415) and TN (MDA-MB231 and MDA-MB468) breast cancer cell lines. We have tested the effects of INK1402 and BEZ235 on the, (a) cell survival/proliferation, (b) downstream signaling pathways for proliferation and (c) 3D ON-TOP-colony formation. Results: Here, we demonstrate that 1) both PIK3CA mutated and PTEN null or mutated breast cancer cells (ER+ and TN) are sensitive to BEZ235 (∼IC50 7 nM-30 nM), 2) only PIK3CA mutated cells (not PTEN loss-of-function cell lines) are sensitive to INK1402 (∼IC50 2 µM-12 µM), 3) anti-clonogenic growth property (3D-ON TOP colony formation assay) of INK1402 is more pronounced (80%-100%) in PIK3CA mutated cells as compared to PTEN loss-of-function cells (∼50%-60%), 4) BEZ235 shows anti-clonogenic property (3D-ON TOP colony formation assay) in all cell lines (∼60%-80%), 5) INK1402 and BEZ235 differentially inhibit PI3K-AKT-mTOR pathway and RAS-MAPK pathway in PIK3CA mutated, PTEN mutated (ER+), and PTEN null (TN) breast cancer cell lines: a) INK1402 is significantly more effective in PIK3CA mutated cell lines as compared to PTEN null or mutated cell lines, b) BEZ235 blocks the activation of PI3K-mTOR pathway components (p-AKT, p-S6RP) in both PIK3CA mutated and PTEN null or mutated cell lines, and c) interestingly, INK1402 blocks ERK activation in PIK3CA mutated cells whereas BEZ235 upregulates ERK activation in both PI3K mutated and PTEN null or mutated cell lines. Conclusion: These findings confirm the mutually exclusive behavior of PIK3CA mutation and PTEN loss in breast tumor models (Ellis MJ et al Cancer Research 2009; Russillo M et al JCO 2011). Our initial finding may provide a rationale to guide selection of patients who may benefit from PI3K-isoform (p110α)-specific inhibitor or PI3K/mTOR dual inhibitor therapy, and highlights the importance of accurately accessing the expression/functional status of PIK3CA or PTEN status in breast tumor samples. Acknowledgement: We sincerely thank to Novartis and Intellikine Inc for proving us with BEZ235 and INK1402 respectively. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2227. doi:1538-7445.AM2012-2227

Background: The PI3K-AKT-mTOR pathway is commonly activated in breast cancers due to the amplification of receptor tyrosine kinase (HER2), the mutation of PIK3CA or the loss of expression/function of PTEN. About 20% of HER2+ breast cancer patients have PIK3CA mutation, which has resulted in a trend toward shorter progression-free survival with trastuzumab-based therapy. Resistance (intrinsic or acquired) to trastuzumab is a significant clinical challenge, partly due to the overriding activation of PI3K-AKT-mTOR pathway. The PI3K pathway activation leads to stimulation of the key growth and proliferation regulatory kinase, mTOR which can be blocked by allosteric inhibitors (rapalogous) or by ATP-comptetive mTOR kinase inhibitor (TORC1/2). Purpose: We investigated the effects of INK128; a potent and selective TORC1/2 kinase inhibitor alone or in conjunction with trastuzumab in HER2 amplified breast tumor cell lines. We also sought to identify the molecular response determinants of mTOR kinase inhibitor predicting potent activity in HER2+/trastuzumab-resistant cell lines. Experimental Design: Here, we used the HER2 amplified trastuzumab-sensitive breast tumor cell line (BT474), the trastuzumab-resistant breast tumor cell line (BT474HR) and HER2 amplified/PIK3CA mutated breast tumor cell lines (HCC1954, UACC893). Results: We demonstrate that 1) HER2+ cells are sensitive to INK128 (IC50 ∼40nM), 2) INK128 is also effective in trastuzumab-resistant and PIK3CA mutaed/HER2+ breast tumor cells (IC50 ∼20 and 20-30nM respectively), 3) INK128 is mechanistically distinct from rapalogous by a more potent and comprehensive inhibition of PI3K-AKT-mTOR signaling network: a) avoids S6K inhibition-mediated feedback activation of PI3K-AKT and b) abrogates 4EBP1 phosphorylation; 4) ligand-induced HIF1α accumulation is inhibited by prior treatment of INK128, and 5) the combination of trastuzumab plus INK128 more effectively blocked PI3K-AKT-mTOR signaling and HIF1α accumulation both in parental and trastuzumab-resistant cells. Conclusion: Our results suggest that i) therapeutic targeting of PI3K-AKT-mTOR signaling should be effective in abrogating resistance to trastuzumab therapy in HER2+ breast cancer, ii) combination of trastuzumab and INK128 is a promising treatment approach for HER2 overexpressed as well as trastuzumab-resistant breast cancer patients and iii) dual TORC1/2 inhibitor also mitigates the feedback activation of AKT caused by selective inhibition of mTORC1, and because of this, INK128 may yield greater therapeutic benefit in breast cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2240. doi:1538-7445.AM2012-2240

Introduction: Identification of the driving genetic alteration(s) (e.g. BRCA, PTEN) and deregulated signaling pathway(s) are critical for the successful discovery of molecular targets in Triple Negative Breast Cancer (TNBC). Understanding of the biology of TN tumor cells has resulted in the recognition of a few molecular targets for the development of novel therapeutics including, (1) cell surface receptor tyrosine kinase(s) (RTKs, e.g. EGFR), (2) signaling pathway(s) (PI3K-mTOR, RAS-MAPK), and (3) DNA-damage (chemo- or radiotherapy) repair pathway. We hypothesize that the genetic background (expression of RTKs, BRCA mutations, absence of PTEN or activating mutations of PIK3CA / RAF) influences the response of TNBC cells to a combination treatment of drugs. Methods: We tested the effects of combination of EGFR/VEGFR inhibitor (vandetanib) with PARPi (Olaparib) in presence of DNA-damaging agent (carboplatin) on, (a) cell survival/proliferation and their, signaling marker(s), (b) integrin-directed migration, (c) fibronectin-directed matrigel-invasion, (d) adhesion-dependent survival, (e) vascular mimicry (VM), and (f) clonogenic survival in TNBC cell lines with high expression of EGFR (MDA-MB468, SUM149), BRCA mutations (HCC1937, SUM149), no expression of PTEN protein (HCC70, HCC1937, MDA-MB468, SUM149), PIK3CA mutation (BT20), and RAS/RAF mutation (MDA-MB231). Results: Data showed that, (1) although EC50s ranged from 5-15 µM for vandetanib in cells, the PTEN-null cells exhibited comparatively favorable EC50s, (2) vandetanib (10 µM) inhibited phosphorylation of AKT (S473 & T308), S6RP, 4EBP1 and ERK by 1 hour, (3) MDA-MB468 cell line was the most sensitive to vandetanib (∼ 0.05 µM) when combined with 10 µM fixed dose of Olaparib, and (4) a combination of vandetanib with Olaparib plus carboplatin time dependently increased caspase-3 and PARP cleavage, inhibited VM (6, 24 h), blocked fibronectin-directed migration, and suppressed clonogenic growth to a greater extent in PTEN-null cells lines. Conclusion: Anti-proliferative/pro-apoptotic, and anti-migratory/invasive effects of vandetanib (alone or in combination with carboplatin plus Olaparib) were most prominent in PTEN-null and high EGFR-expressing cells. However, given that the inhibitory activity of olaparib occurred at relatively high concentrations we are currently pursuing studies to refine the dose response relationship. In addition we are examining (1) the mechanistic relationship between the anti-proliferative/pro-apoptotic effects and the effectors status of EGFR/ PI3K pathway following treatment with vandetanib (in combination with PARPi plus temozolomide), and (2) effect of vandetanib on the hypoxic-response of tumor and endothelial cells, the results of which will be presented in the meeting. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2250. doi:1538-7445.AM2012-2250

Introduction: Recent understanding of the biology of Triple Negative (TN) tumor cells has resulted in the recognition of following molecular targets for the development of novel therapeutics, (1) cell surface receptor tyrosine kinases (RTKs, e.g. EGFR, IGFR, c-MET, FGFR), (2) intracellular signaling pathway(s) (PI3K-AKT-mTOR, RAS-MAPK-ERK), and (3) DNA-damage (chemo- or radiotherapy) repair pathway. INK128 is an orally bioavailable, potent and selective ATP site kinase inhibitor of mTOR complexes TORC1 and TORC2 that together play a crucial role in regulating tumor cell growth, metabolism and motility. INK128 is structurally and mechanistically distinct from allosteric rapamycin-based mTOR inhibitors such as RAD001. Methods: We tested effects of INK128 (alone or in combination with carboplatin and ABT888) on, (a) cell survival/proliferation, (b) cell signaling marker(s) of proliferation, (c) fibronectin-mediated migration, (d) fibronectin-directed matrigel-invasion, and (e) clonogenic survival (3D-ON-TOP assay) in different TNBT cell lines with high expression of EGFR (MDA-MB468, SUM149), BRCA mutations (HCC1937, SUM149) no expression of PTEN protein (HCC70, HCC1937, MDA-MB468, SUM149), PIK3CA mutation (BT20) and RAS/RAF mutation (MDA-MB231). Results: Data showed that, (1) although the range of EC50s for INK128 varied from 50 nM-500 nM in different TNBT cells, the PTEN-null cells exhibited favorable EC50s compared to the rest of the cell lines (with exception to HCC1937), (2) inhibition of phosphorylation of AKT (S473), S6RP, and 4EBP1 was observed following INK128 treatment (100 nM and 200 nM) as early as 6 hours, (3) treatment with 200 nM INK128 for 24 hours differentially blocked pERK in PTEN-null MDA-MB468 as compared to MDA-MB231 cells, (4) INK128 treatment (100 nM) inhibited migration of different TNBT cells (as compared to 2 uM RAD001, allosteric, partial TORC1 inhibitor)) and the inhibition was differentially pronounced in PTEN-null TNBT cells lines, (5) INK128 treatment (100 nM) also blocked invasion of MDA-MB468 cells, and (6) INK128 dose-dependently blocked clonogenic growth of TNBT cells. This effect was potentiated in the presence of ABT888 (10uM; small molecule PARP inhibitor) plus carboplatin (10uM; chemotherapeutic agent). Conclusion: INK128 (alone or in combination with carboplatin and ABT888) has anti-proliferative effect on TNBT cells. INK128 has anti-migratory and anti-invasive effects on TNBT cells. Interestingly, the anti-migratory effect of INK128 was most prominent in PTEN-null TNBT cells. We are currently pursuing studies to test the effect of INK128 on the endothelial cells, the results of which will be presented in the meeting. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2230. doi:1538-7445.AM2012-2230

Background: HER2 overexpression occurs in 20-25% of patients with breast cancer and is associated with aggressive disease and decreased survival. HER2 activates multiple cellular signaling pathways including the PI3K-AKT-mTOR pathway. The sustained activation of the PI3K-AKT-mTOR pathway or the activating mutation of PIK3CA (p110α) is one of the major causes of drug resistance including trastuzumab. Purpose: Inhibitors of mTOR1 have been shown to be active in patients with solid tumors. As the phosphatidylinositol 3-Kianse (PI3K) pathway activates numerous other kinases, transcription factors, and proteins associated with cell growth/survival and apoptosis besides mammalian target of rapamycin (mTOR), suppression of this pathway upstream of mTOR may be more effective than inhibition of mTOR1 in HER2+ breast cancer models. Experimental Design: To examine this possibility, the dual pan-PI3K/mTOR inhibitor, BEZ235 was compared with mTOR1 inhibitor, RAD001 in trastuzumab-sensitive HER2+ (BT474 and SKBR3), trastuzumab-resistant (BT474HR), and PIK3CA mutated/HER2+ breast cancer cells (HCC1954 and U893) Results: Treatment of HER2+ breast cancer cell lines with BEZ235 or RAD001 in vitro showed 1) RAD001 mediated AKT activation was blocked when cells were treated with BEZ235, 2) BEZ235 dose- and time-dependently blocked AKT phosphorylation (both at Ser473 and Thr308), 3) both drugs completely blocked the activation P70S6K, but BEZ235 more efficiently blocked 4EBP1 phosphorylation than RAD001, 4) ERK activation was significantly attenuated by BEZ235, while inhibition of mTOR1 by RAD001 lead to activated ERK, 5) BEZ235 was significantly more effective than RAD001 in reducing HIF1α expression following heregulin stimulation, 6) activation of caspase3 (from the expression level of cleaved caspase3) was also greater following treatment with BEZ235 than RAD001, and 7) integrin-dependent breast tumor cell migration was significantly abrogated with BEZ235 in association with inhibition of RAC1-GTP, but this was not seenwith RAD001. Conclusion: Our preclinical in vitro data demonstrate that concurrent inhibition of PI3K and mTOR is likely to be a more effective strategy in the treatment of both sensitive and resistant HER2+ breast cancers than the inhibition of mTOR1 alone. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4496. doi:10.1158/1538-7445.AM2011-4496

e13510 Background: Paclitaxel is a chemotherapeutic agent that induces apoptosis of tumor cells in several cancer types including ovarian and breast cancer. However, the neurotoxic side effects of ...

En este trabajo describimos las tendencias halladas en el uso de los tiempos aspectuales de pasado del español, esto es, pretérito indefinido (PIN) e imperfecto (PIM) de indicativo, en la producción escrita de aprendices sinohablantes de ELE/L2 de distintos tipos de pruebas, tanto cerradas (prueba de cloze) como abiertas y semiabiertas (redacciones semi-guiadas), que forman parte del corpus Gushi-ELE, de secuencias narrativas producidas por estudiantes de niveles B1 a C1 (del MCER). Basándonos en este análisis, proponemos implicaciones didácticas de la enseñanza de los tiempos aspectuales del español para los aprendices chinos.