TPX2 overexpression promotes sensitivity to dasatinib in breast cancer by activating YAP transcriptional signaling.

Chromosomal instability (CIN) is a hallmark of cancer aggressiveness, providing genetic plasticity and tumor heterogeneity that allows the tumor to evolve and adapt to stress conditions. CIN is considered a cancer therapeutic biomarker because healthy cells do not exhibit CIN. Despite recent efforts to identify therapeutic strategies related to CIN, the results obtained have been very limited. CIN is characterized by a genetic signature where a collection of genes, mostly mitotic regulators, are overexpressed in CIN-positive tumors, providing aggressiveness and poor prognosis. We attempted to identify new therapeutic strategies related to CIN genes by performing a drug screen, using cells that individually express CIN-associated genes in an inducible manner. We find that the overexpression of targeting protein for Xklp2 (TPX2) enhances sensitivity to the proto-oncogene c-Src (SRC) inhibitor dasatinib due to activation of the Yes-associated protein 1 (YAP) pathway. Furthermore, using breast cancer data from The Cancer Genome Atlas (TCGA) and a cohort of cancer-derived patient samples, we find that both TPX2 overexpression and YAP activation are present in a significant percentage of cancer tumor samples and are associated with poor prognosis; therefore, they are putative biomarkers for selection for dasatinib therapy.

Nivolumab plus platinum-doublet chemotherapy in treatment-naive patients with advanced grade 3 Neuroendocrine Neoplasms of gastroenteropancreatic or unknown origin: The multicenter phase 2 NICE-NEC trial (GETNE-T1913).

The prognosis of patients with advanced high-grade (G3) digestive neuroendocrine neoplasms (NENs) is rather poor. The addition of immune checkpoint inhibition to platinum-based chemotherapy may improve survival. NICE-NEC (NCT03980925) is a single-arm, phase II trial that recruited chemotherapy-naive, unresectable advanced or metastatic G3 NENs of gastroenteropancreatic (GEP) or unknown origin. Patients received nivolumab 360 mg intravenously (iv) on day 1, carboplatin AUC 5 iv on day 1, and etoposide 100 mg/m2/d iv on days 1-3, every 3 weeks for up to six cycles, followed by nivolumab 480 mg every 4 weeks for up to 24 months, disease progression, death or unacceptable toxicity. The primary endpoint was the 12-month overall survival (OS) rate (H0 50%, H1 72%, ß 80%, α 5%). Secondary endpoints were objective response rate (ORR), duration of response (DoR), progression-free survival (PFS), and safety. From 2019 to 2021, 37 patients were enrolled. The most common primary sites were the pancreas (37.8%), stomach (16.2%) and colon (10.8%). Twenty-five patients (67.6%) were poorly differentiated carcinomas (NECs) and/or had a Ki67 index >55%. The ORR was 56.8%. Median PFS was 5.7 months (95%CI: 5.1-9) and median OS 13.9 months (95%CI: 8.3-Not reached), with a 12-month OS rate of 54.1% (95%CI: 40.2-72.8) that did not meet the primary endpoint. However, 37.6% of patients were long-term survivors (>2 years). The safety profile was consistent with previous reports. There was one treatment-related death. Nivolumab plus platinum-based chemotherapy was associated with prolonged survival in over one-third of chemonaïve patients with G3 GEP-NENs, with a manageable safety profile.

Gasdermin-B Pro-Tumor Function in Novel Knock-in Mouse Models Depends on the in vivo Biological Context.

Gasdermins (GSDM) genes play complex roles in inflammatory diseases and cancer. Gasdermin-B (GSDMB) is frequently upregulated in human cancers, especially in HER2-amplified breast carcinomas, and can promote diverse pro-tumor functions (invasion, metastasis, therapy-resistance). In particular, the GSDMB shortest translated variant (isoform 2; GSDMB2) increases aggressive behavior in breast cancer cells. Paradoxically, GSDMB can also have tumor suppressor (cell death induction) effects in specific biological contexts. However, whether GSDMB has inherent oncogenic, or tumor suppressor function in vivo has not been demonstrated yet in preclinical mouse models, since mice lack GSDMB orthologue. Therefore, to decipher GSDMB cancer functions in vivo we first generated a novel knock-in mouse model (R26-GB2) ubiquitously expressing human GSDMB2. The comprehensive histopathological analysis of multiple tissues from 75 animals showed that nucleus-cytoplasmic GSDMB2 expression did not clearly affect the overall frequency nor the histology of spontaneous neoplasias (mostly lung carcinomas), but associated with reduced incidence of gastric tumors, compared to wildtype animals. Next, to assess specifically the GSDMB2 roles in breast cancer, we generated two additional double transgenic mouse models, that co-express GSDMB2 with either the HER2/NEU oncogene (R26-GB2/MMTV-NEU mice) or the Polyoma middle-T antigen (R26-GB2/MMTV-PyMT) in breast tumors. Consistent with the pro-tumor effect of GSDMB in HER2+ human breast carcinomas, R26-GB2/MMTV-NEU GSDMB2-positive mice have double breast cancer incidence than wildtype animals. By contrast, in the R26-GB2/MMTV-PyMT model of fast growing and highly metastatic mammary tumors, GSDMB2 expression did not significantly influence cancer development nor metastatic potential. In conclusion, our data prove that GSDMB2 in vivo pro-tumor effect is evidenced only in specific biological contexts (in concert with the HER2 oncogene), while GSDMB2 alone does not have overall intrinsic oncogenic potential in genetically modified mice. Our novel models are useful to identify the precise stimuli and molecular mechanisms governing GSDMB functions in neoplasias and can be the basis for the future development of additional tissue-specific and context-dependent cancer models.

[Venolymphatic malformation with bone erosion. An unusual affectation in these lesions]. / Malformación venolinfática con erosión ósea. Una afectación rara en estas lesiones.

A 30 year old male presented with a cutaneous lesion on the distal area of the 5th toe with involvement of the outer edges. Macroscopically, it was a 1cm violaceous and keratotic lesion. Radiography showed an increase in soft tissue, possibly due to a vascular lesion. MRI showed a hyper-intense signal with erosion of the distal phalanx compatible with a low-flow vascular malformation. The distal phalanx was amputated. Histopathology revealed a lesion formed by venous and D2-40 positive lymphatic vessels. This case highlights the fact that even minimal skin involvement in vascular malformations may conceal an important deeper lesion, such as erosion of the cortical bone.

Malformación venolinfática con erosión ósea. Una afectación rara en estas lesiones / Venolymphatic malformation with bone erosion. An unusual affectation in these lesions

Paciente varón de 30 años que consultó por una lesión en el 5.° dedo del pie derecho con afectación cutánea del pulpejo y de todo el borde externo. Macroscópicamente se trataba de una lesión violácea con superficie queratósica de 1cm. En la radiografía simple se objetivó un aumento de partes blandas, de posible origen vascular. La resonancia mostró una lesión que erosionaba la cortical de la falange distal, de señal muy hiperintensa compatible con malformación vascular de bajo flujo. Se realizó extirpación de la lesión mediante amputación de la falange distal y a nivel histológico se observó una lesión formada por vasos de tipo venoso y tipo linfático que eran D2-40 positivos. En las malformaciones vasculares la participación cutánea, aunque sea mínima, puede esconder una importante afectación profunda. Cuando asientan sobre planos óseos hay que descartar la erosión de la cortical del hueso subyacente (AU)

A 30 year old male presented with a cutaneous lesion on the distal area of the 5th toe with involvement of the outer edges. Macroscopically, it was a 1cm violaceous and keratotic lesion. Radiography showed an increase in soft tissue, possibly due to a vascular lesion. MRI showed a hyper-intense signal with erosion of the distal phalanx compatible with a low-flow vascular malformation. The distal phalanx was amputated. Histopathology revealed a lesion formed by venous and D2-40 positive lymphatic vessels. This case highlights the fact that even minimal skin involvement in vascular malformations may conceal an important deeper lesion, such as erosion of the cortical bone (AU)