Lisocabtagene maraleucel as second-line therapy in adults with relapsed or refractory large B-cell lymphoma who were not intended for haematopoietic stem cell transplantation (PILOT): an open-label, phase 2 study.

BACKGROUND: Patients with relapsed or refractory large B-cell lymphoma after first-line treatment who are not intended for haematopoietic stem-cell transplantation (HSCT) have poor outcomes and limited treatment options. We assessed the antitumour activity and safety of lisocabtagene maraleucel, an autologous, CD19-directed chimeric antigen receptor (CAR) T-cell product, as second-line treatment in adults with relapsed or refractory large B-cell lymphoma not intended for HSCT. METHODS: PILOT, an open-label, phase 2 trial done at 18 clinical sites in the USA, included adults aged 18 years or older who had relapsed or refractory large B-cell lymphoma and PET-positive disease, had received first-line therapy containing an anthracycline and a CD20-targeted agent, were not intended for HSCT by their physician, and met at least one prespecified transplantation not intended criterion. Patients received lymphodepleting chemotherapy (intravenous fludarabine 30 mg/m2 and intravenous cyclophosphamide 300 mg/m2 daily for 3 days) followed 2-7 days later by two sequential lisocabtagene maraleucel infusions (equal target doses of CD8+ and CD4+ CAR+ T cells for a total target dose of 100 × 106 CAR+ T cells). The primary endpoint was the overall response rate and was assessed in all patients who received lisocabtagene maraleucel and had confirmed PET-positive disease before lisocabtagene maraleucel administration based on an independent review committee according to the Lugano 2014 criteria. Safety was assessed in all patients who received lisocabtagene maraleucel. Patient follow-up is ongoing. This study is registered with ClinicalTrials.gov, NCT03483103. FINDINGS: Between July 26, 2018, and Sept 24, 2021 (data cutoff for the primary analysis), 74 patients underwent leukapheresis and 61 received lisocabtagene maraleucel (efficacy and safety sets); median age was 74 years (IQR 70-78), 24 (39%) patients were women versus 37 (61%) men, and 54 (89%) patients were White. 16 (26%) of 61 patients had an Eastern Cooperative Oncology Group performance status of 2, 33 (54%) had refractory disease, 13 (21%) relapsed within 1 year of first-line therapy, and 15 (25%) relapsed after 12 months of first-line therapy. Median on-study follow-up was 12·3 months (IQR 6·1-18·0). 49 (80% [95% CI 68-89]; p<0·0001) patients had an overall response. The most common grade 3 or worse treatment-emergent adverse events were neutropenia (29 [48%] patients), leukopenia (13 [21%]), and thrombocytopenia (12 [20%]). Lisocabtagene maraleucel-related serious treatment-emergent adverse events were reported in 13 (21%) patients. There were no treatment-related deaths. Cytokine release syndrome occurred in 23 (38%; grade 3 in one) patients and neurological events in 19 (31%; grade 3 in three) patients, with no grade 4 events or deaths. INTERPRETATION: These results support lisocabtagene maraleucel as a potential second-line treatment in patients with large B-cell lymphoma for whom HSCT is not intended. FUNDING: Juno Therapeutics, a Bristol-Myers Squibb company.

Mutual epithelium-macrophage dependency in liver carcinogenesis mediated by ST18.

The ST18 gene has been proposed to act either as a tumor suppressor or as an oncogene in different human cancers, but direct evidence for its role in tumorigenesis has been lacking thus far. Here, we demonstrate that ST18 is critical for tumor progression and maintenance in a mouse model of liver cancer, based on oncogenic transformation and adoptive transfer of primary precursor cells (hepatoblasts). ST18 messenger RNA (mRNA) and protein were detectable neither in normal liver nor in cultured hepatoblasts, but were readily expressed after subcutaneous engraftment and tumor growth. ST18 expression in liver cells was induced by inflammatory cues, including acute or chronic inflammation in vivo, as well as coculture with macrophages in vitro. Knocking down the ST18 mRNA in transplanted hepatoblasts delayed tumor progression. Induction of ST18 knockdown in pre-established tumors caused rapid tumor involution associated with pervasive morphological changes, proliferative arrest, and apoptosis in tumor cells, as well as depletion of tumor-associated macrophages, vascular ectasia, and hemorrhage. Reciprocally, systemic depletion of macrophages in recipient animals had very similar phenotypic consequences, impairing either tumor development or maintenance, and suppressing ST18 expression in hepatoblasts. Finally, RNA sequencing of ST18-depleted tumors before involution revealed down-regulation of inflammatory response genes, pointing to the suppression of nuclear factor kappa B-dependent transcription. CONCLUSION: ST18 expression in epithelial cells is induced by tumor-associated macrophages, contributing to the reciprocal feed-forward loop between both cell types in liver tumorigenesis. Our findings warrant the exploration of means to interfere with ST18-dependent epithelium-macrophage interactions in a therapeutic setting. (Hepatology 2017;65:1708-1719).

Genetic dissection of the miR-17~92 cluster of microRNAs in Myc-induced B-cell lymphomas.

The miR-17 approximately 92 cluster is frequently amplified or overexpressed in human cancers and has emerged as the prototypical oncogenic polycistron microRNA (miRNA). miR-17 approximately 92 is a direct transcriptional target of c-Myc, and experiments in a mouse model of B-cell lymphomas have shown cooperation between these two oncogenes. However, both the molecular mechanism underlying this cooperation and the individual miRNAs that are responsible for it are unknown. By using a conditional knockout allele of miR-17 approximately 92, we show here that sustained expression of endogenous miR-17 approximately 92 is required to suppress apoptosis in Myc-driven B-cell lymphomas. Furthermore, we show that among the six miRNAs that are encoded by miR-17 approximately 92, miR-19a and miR-19b are absolutely required and largely sufficient to recapitulate the oncogenic properties of the entire cluster. Finally, by combining computational target prediction, gene expression profiling, and an in vitro screening strategy, we identify a subset of miR-19 targets that mediate its prosurvival activity.

Intact p53-dependent responses in miR-34-deficient mice.

MicroRNAs belonging to the miR-34 family have been proposed as critical modulators of the p53 pathway and potential tumor suppressors in human cancers. To formally test these hypotheses, we have generated mice carrying targeted deletion of all three members of this microRNA family. We show that complete inactivation of miR-34 function is compatible with normal development in mice. Surprisingly, p53 function appears to be intact in miR-34-deficient cells and tissues. Although loss of miR-34 expression leads to a slight increase in cellular proliferation in vitro, it does not impair p53-induced cell cycle arrest or apoptosis. Furthermore, in contrast to p53-deficient mice, miR-34-deficient animals do not display increased susceptibility to spontaneous, irradiation-induced, or c-Myc-initiated tumorigenesis. We also show that expression of members of the miR-34 family is particularly high in the testes, lungs, and brains of mice and that it is largely p53-independent in these tissues. These findings indicate that miR-34 plays a redundant function in the p53 pathway and suggest additional p53-independent functions for this family of miRNAs.

Comparison of two PCR methods for detection of Leptospira interrogans in formalin-fixed and paraffin-embedded tissues.

In this study we compared two polymerase chain reaction (PCR) methods using either 16S ribosomal RNA (rRNA) or 23S rRNA gene primers for the detection of different Leptospira interrogans serovars. The performance of these two methods was assessed using DNA extracted from bovine tissues previously inoculated with several bacterial suspensions. PCR was performed on the same tissues before and after the formalin-fixed, paraffin-embedding procedure (FFPE tissues). The 23S rDNA PCR detected all fresh and FFPE positive tissues while the 16S rDNA-based protocol detected primarily the positive fresh tissues. Both methods are specific for pathogenic L. interrogans. The 23S-based PCR method successfully detected Leptospira in four dubious cases of human leptospirosis from archival tissue specimens and one leptospirosis-positive canine specimen. A sensitive method for leptospirosis identification in FFPE tissues would be a useful tool to screen histological specimen archives and gain a better assessment of human leptospirosis prevalence, especially in tropical countries, where large outbreaks can occur following the rainy season.

miR-20b modulates VEGF expression by targeting HIF-1 alpha and STAT3 in MCF-7 breast cancer cells.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate the expression of different genes, including genes involved in cancer progression. A functional link between hypoxia, a key feature of the tumor microenvironment, and miRNA expression has been documented. We investigated whether and how miR-20b can regulate the expression of vascular endothelial growth factor (VEGF) in MCF-7 breast cancer cells under normoxic and hypoxia-mimicking conditions (CoCl(2) exposure). Using immunoblotting, ELISA, and quantitative real-time PCR, we demonstrated that miR-20b decreased VEGF protein levels at 4 and 24 h following CoCl(2) treatment, and VEGF mRNA at 4 h of treatment. In addition, miR-20b reduced VEGF protein expression in untreated cells. Next, we investigated the molecular mechanism by which pre-miR-20b can affect VEGF transcription, focusing on hypoxia inducible factor 1 (HIF-1) and signal transducer and activator of transcription 3 (STAT3), transcriptional inducers of VEGF and putative targets of miR-20b. Downregulation of VEGF mRNA by miR-20b under a 4 h of CoCl(2) treatment was associated with reduced levels of nuclear HIF-1 alpha subunit and STAT3. Chromatin immunoprecipitation (ChIP) assays revealed that HIF-1 alpha, but not STAT3, was recruited to the VEGF promoter following the 4 h of CoCl(2) treatment. This effect was inhibited by transfection of cells with pre-miR-20b. In addition, using siRNA knockdown, we demonstrated that the presence of STAT3 is necessary for CoCl(2)-mediated HIF-1 alpha nuclear accumulation and recruitment on VEGF promoter. In summary, this report demonstrates, for the first time, that the VEGF expression in breast cancer cells is mediated by HIF-1 and STAT3 in a miR-20b-dependent manner.

Expression of angiogenic regulators, VEGF and leptin, is regulated by the EGF/PI3K/STAT3 pathway in colorectal cancer cells.

Both leptin and vascular endothelial growth factor (VEGF) are growth and angiogenic cytokines that are upregulated in different types of cancer and have been implicated in neoplastic progression. Here we investigated the molecular mechanism by which leptin and VEGF expression are regulated in colon cancer by epidermal growth factor (EGF). In colon cancer cell line HT-29, EGF induced the binding of signal transducer and activator transcription 3 (STAT3) to STAT3 consensus motifs within the VEGF and leptin promoters and stimulated leptin and VEGF mRNA and protein synthesis. All these EGF effects were significantly blocked when HT-29 cells were treated with an inhibitor of the phosphoinositide 3-kinase (PI3K) pathway, LY294002, or with small interfering RNA (siRNA) targeting STAT3. Thus, our study identified the EGF/PI3K/STAT3 signaling as an essential pathway regulating VEGF and leptin expression in EGF-responsive colon cancer cells. This suggests that STAT3 pathways might constitute attractive pharmaceutical targets in colon cancer patients where anti-EGF receptor drugs are ineffective.

Therapeutic synergy between tigecycline and venetoclax in a preclinical model of MYC/BCL2 double-hit B cell lymphoma.

High-grade B cell lymphomas with concurrent activation of the MYC and BCL2 oncogenes, also known as double-hit lymphomas (DHL), show dismal prognosis with current therapies. MYC activation sensitizes cells to inhibition of mitochondrial translation by the antibiotic tigecycline, and treatment with this compound provides a therapeutic window in a mouse model of MYC-driven lymphoma. We now addressed the utility of this antibiotic for treatment of DHL. BCL2 activation in mouse Eµ-myc lymphomas antagonized tigecycline-induced cell death, which was specifically restored by combined treatment with the BCL2 inhibitor venetoclax. In line with these findings, tigecycline and two related antibiotics, tetracycline and doxycycline, synergized with venetoclax in killing human MYC/BCL2 DHL cells. Treatment of mice engrafted with either DHL cell lines or a patient-derived xenograft revealed strong antitumoral effects of the tigecycline/venetoclax combination, including long-term tumor eradication with one of the cell lines. This drug combination also had the potential to cooperate with rituximab, a component of current front-line regimens. Venetoclax and tigecycline are currently in the clinic with distinct indications: Our preclinical results warrant the repurposing of these drugs for combinatorial treatment of DHL.

The mitochondrial translation machinery as a therapeutic target in Myc-driven lymphomas.

The oncogenic transcription factor Myc is required for the progression and maintenance of diverse tumors. This has led to the concept that Myc itself, Myc-activated gene products, or associated biological processes might constitute prime targets for cancer therapy. Here, we present an in vivo reverse-genetic screen targeting a set of 241 Myc-activated mRNAs in mouse B-cell lymphomas, unraveling a critical role for the mitochondrial ribosomal protein (MRP) Ptcd3 in tumor maintenance. Other MRP-coding genes were also up regulated in Myc-induced lymphoma, pointing to a coordinate activation of the mitochondrial translation machinery. Inhibition of mitochondrial translation with the antibiotic Tigecycline was synthetic-lethal with Myc activation, impaired respiratory activity and tumor cell survival in vitro, and significantly extended lifespan in lymphoma-bearing mice. We have thus identified a novel Myc-induced metabolic dependency that can be targeted by common antibiotics, opening new therapeutic perspectives in Myc-overexpressing tumors.

Comparison of two PCR methods for detection of Leptospira interrogans in formalin-fixed and paraffin-embedded tissues

In this study we compared two polymerase chain reaction (PCR) methods using either 16S ribosomal RNA (rRNA) or 23S rRNA gene primers for the detection of different Leptospira interrogans serovars. The performance of these two methods was assessed using DNA extracted from bovine tissues previously inoculated with several bacterial suspensions. PCR was performed on the same tissues before and after the formalin-fixed, paraffin-embedding procedure (FFPE tissues). The 23S rDNA PCR detected all fresh and FFPE positive tissues while the 16S rDNA-based protocol detected primarily the positive fresh tissues. Both methods are specific for pathogenic L. interrogans. The 23S-based PCR method successfully detected Leptospira in four dubious cases of human leptospirosis from archival tissue specimens and one leptospirosis-positive canine specimen. A sensitive method for leptospirosis identification in FFPE tissues would be a useful tool to screen histological specimen archives and gain a better assessment of human leptospirosis prevalence, especially in tropical countries, where large outbreaks can occur following the rainy season.