The high-grade pulmonary neuroendocrine tumors, small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC), remain among the most deadly malignancies. Therapies that effectively ...target and kill tumor-initiating cells (TICs) in these cancers should translate to improved patient survival. Patient-derived xenograft (PDX) tumors serve as excellent models to study tumor biology and characterize TICs. Increased expression of delta-like 3 (DLL3) was discovered in SCLC and LCNEC PDX tumors and confirmed in primary SCLC and LCNEC tumors. DLL3 protein is expressed on the surface of tumor cells but not in normal adult tissues. A DLL3-targeted antibody-drug conjugate (ADC), SC16LD6.5, comprised of a humanized anti-DLL3 monoclonal antibody conjugated to a DNA-damaging pyrrolobenzodiazepine (PBD) dimer toxin, induced durable tumor regression in vivo across multiple PDX models. Serial transplantation experiments executed with limiting dilutions of cells provided functional evidence confirming that the lack of tumor recurrence after SC16LD6.5 exposure resulted from effective targeting of DLL3-expressing TICs. In vivo efficacy correlated with DLL3 expression, and responses were observed in PDX models initiated from patients with both limited and extensive-stage disease and were independent of their sensitivity to standard-of-care chemotherapy regimens. SC16LD6.5 effectively targets and eradicates DLL3-expressing TICs in SCLC and LCNEC PDX tumors and is a promising first-in-class ADC for the treatment of high-grade pulmonary neuroendocrine tumors.
Diffuse malignant mesothelioma of the pleura is a highly aggressive tumor typically associated with short survival. ALCAM (CD166), a type I transmembrane protein, is a member of the immunoglobulin ...superfamily. In normal cells, ALCAM regulates physiological processes such as angiogenesis and immune response. In cancer, it is associated with neoplastic progression, including invasion, migration, and metastasis. Furthermore, ALCAM is considered one of the cancer stem cell markers such as ALDH1 (ALDH1A1) and SALL4. The PD-L1 (CD274)/PD-1 (PDCD1, CD279) pathway is crucial for the modulation of immune responses in normal cells. Nevertheless, pathologic activation of the PD-L1/PD-1 pathway participates in immune evasion by tumor cells. Many PD-L1–expressing tumor cells have been identified in different types of cancer, including malignant mesothelioma. In this study, 175 well-characterized primary diffuse pleural mesotheliomas, including the epithelioid (n = 148), biphasic (n = 15), and sarcomatoid (n = 12) histotypes, were evaluated immunohistochemically for cancer stem cell markers (ALCAM, ALDH1, and SALL4) and PD-L1 expression. Twenty-five percent of the mesotheliomas (43/175) expressed ALCAM, whereas ALDH1 and SALL4 positivity was seen in 1% to 2% of cases. Thirty-three percent of the analyzed tumors (57/175) contained PD-L1–positive cells. Overall survival was significantly decreased in the cohort of patients with ALCAM- or PD-L1–positive tumors (both P < .01). Furthermore, the multivariate Cox hazards regression analysis identified ALCAM and PD-L1 (both P < 0.01) as potential independent risk factors. Thus, a combination of these 2 markers might be useful for prognostication and planning the treatment of patients with malignant pleural mesothelioma.
•PD-L1 and stem cell marker expressions were analyzed in malignant mesotheliomas.•PD-L1 and ALCAM were expressed in 33% and 25% of mesothelioma cases, respectively.•The Cox proportional hazards model identified these proteins as independent risk factors for death.
ALK alterations in salivary gland carcinomas Majewska, Hanna; Gorczyński, Adam; Czapiewski, Piotr ...
Virchows Archiv : an international journal of pathology,
05/2021, Letnik:
478, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Salivary gland carcinomas represent a heterogeneous group of poorly characterized head and neck tumors. The purpose of this study was to evaluate
ALK
gene and protein aberrations in a large, ...well-characterized cohort of these tumors. A total of 182 salivary gland carcinomas were tested for anaplastic lymphoma kinase (ALK) positivity by immunohistochemistry (IHC) using the cut-off of 10% positive cells. ALK positive tumors were subjected to FISH analysis and followed by hybrid capture–based next generation sequencing (NGS). Of the 182 tumors, 8 were ALK positive by IHC. Further analysis using hybrid capture NGS analysis revealed a novel
MYO18A
(Exon1-40)-
ALK
(exon 20-29) gene fusion in one case of intraductal carcinoma. Additional genomic analyses resulted in the detection of inactivating mutations in
BRAF
and
TP53
, as well as amplifications of
ERBB2
and
ALK
.
ALK
rearrangements are a rare entity in salivary gland carcinomas. We identified a potentially targetable novel
ALK
fusion in an intraductal carcinoma of minor salivary glands.
Patients with estrogen receptor positive breast cancer are usually receiving an anti-estrogen therapy by either aromatase inhibitors or selective estrogen receptor mediators such as tamoxifen. ...Nevertheless, acquired resistance to tamoxifen under treatment frequently hampers therapy. One proposed explanation for this phenomenon is the interaction of the tumor cells with cells of the tumor microenvironment via the Insulin-like growth factor RNA binding protein 5/B-cell lymphoma 3 (IGFBP5/BCL3) axis. Here we investigated whether a high expression of BCL3 either cytoplasmic or nuclear is associated with the occurrence of a relapse under anti-estrogen therapy in patients. Formaldehyde-fixed, paraffin-embedded samples of 180 breast cancer patients were analyzed for BCL3 expression by immunohistochemistry. An immunoreactive score (IRS) was calculated from staining intensity in cytoplasm and nucleus as well as the percentage of positive tumor cells. These scores were correlated with clinico-pathological parameters using cross-tabulation analysis and patients’ relapse free and overall survival by Kaplan–Meier analysis and Cox regression. A tamoxifen-adapted MCF-7 derived cell line was investigated for BCL3 localization by immunofluorescence. The cytosolic BCL3-IRS significantly correlated with the proliferation marker Ki-67, and with the occurrence of a relapse under tamoxifen treatment. Nuclear score correlated only with tamoxifen-relapse. In survival analysis, both scores were highly significant prognostic factors for relapse free, but not for overall survival. This was especially obvious for estrogen receptor positive and HER2/NEU negative cases as well as lobular breast cancer. Tamoxifen-treated, but not aromatase-treated patients had a poor survival when BCL3 scores were high. A tamoxifen adapted cell line exhibited a reduced expression and mainly nuclear localization of BCL3, compared to the parental estrogen receptor positive cell-line MCF-7. Altogether, these data strongly support a function of BCL3 in tamoxifen resistance and its potential use as a predictive biomarker for tamoxifen resistance.
Therapeutic antibodies to immune checkpoints show promising results. Programmed death-ligand 1 (PD-L1), an immune checkpoint ligand, blocks the cancer immunity cycle by binding the PD-L1 receptor ...(programmed death 1). We investigated PD-L1 protein expression and messenger RNA (mRNA) levels in SCLC.
PD-L1 protein expression and mRNA levels were determined by immunohistochemistry (IHC) with SP142 and Dako 28-8 PD-L1 antibodies and in situ hybridization in primary tumor tissue microarrays in both tumor cells and tumor-infiltrating immune cells (TIICs) obtained from a limited-disease SCLC cohort of 98 patients. An additional cohort of 96 tumor specimens from patients with extensive-disease SCLC was assessed for PD-L1 protein expression in tumor cells with Dako 28-8 antibody only.
The overall prevalence of PD-L1 protein expression in tumor cells was 16.5%. In the limited-disease cohort, the prevalences of PD-L1 protein expression in tumor cells with SP142 and Dako 28-8 were 14.7% and 19.4% (tumor proportion score cutoff ≥1%) and PD-L1 mRNA ISH expression was positive in 15.5% of tumor samples. Increased PD-L1 protein/mRNA expression was associated with the presence of more TIICs (p < 0.05). The extensive-disease cohort demonstrated a 14.9% positivity of PD-L1 protein expression in tumor cells with Dako 28-8 antibody.
A subset of SCLCs is characterized by positive PD-L1 and/or mRNA expression in tumor cells. Higher PD-L1 and mRNA expression correlate with more infiltration of TIICs. The prevalence of PD-L1 in SCLC is lower than that published for NSCLC. The predictive role of PD-L1 expression in SCLC treatment remains to be established.
Adipogenesis associated Mth938 domain containing (AAMDC) represents an uncharacterized oncogene amplified in aggressive estrogen receptor-positive breast cancers. We uncover that AAMDC regulates the ...expression of several metabolic enzymes involved in the one-carbon folate and methionine cycles, and lipid metabolism. We show that AAMDC controls PI3K-AKT-mTOR signaling, regulating the translation of ATF4 and MYC and modulating the transcriptional activity of AAMDC-dependent promoters. High AAMDC expression is associated with sensitization to dactolisib and everolimus, and these PI3K-mTOR inhibitors exhibit synergistic interactions with anti-estrogens in IntClust2 models. Ectopic AAMDC expression is sufficient to activate AKT signaling, resulting in estrogen-independent tumor growth. Thus, AAMDC-overexpressing tumors may be sensitive to PI3K-mTORC1 blockers in combination with anti-estrogens. Lastly, we provide evidence that AAMDC can interact with the RabGTPase-activating protein RabGAP1L, and that AAMDC, RabGAP1L, and Rab7a colocalize in endolysosomes. The discovery of the RabGAP1L-AAMDC assembly platform provides insights for the design of selective blockers to target malignancies having the AAMDC amplification.
Anaplastic thyroid carcinoma is a rare, rapidly progressing, highly aggressive thyroid malignancy. Responses to immune checkpoint inhibitors in mismatch repair-deficient/microsatellite ...instability-high tumours of other locations have shown promising results, and with the extended approval of the PD-1 receptor inhibitor pembrolizumab by the Food and Drug Administration, also anaplastic thyroid cancer (ATC) requires analysis for microsatellite instability (MSI) status.
Systematic research for relevant literature was conducted in different databases. Prevalence, detection methods, and the potential prognostic/predictive value of MSI in view of the available targeted therapies were of special focus.
Selected citations revealed the prevalence of MSI in 7.4%, with mutations in the MSH2 gene (33%) being the most frequent, followed by MSH6 (25%) and MLH1 (16.7%) occurring in the following combinations: MLH1-MSH2 (8.3%), MSH2-MSH6 (8.3%), and MLH3-MSH5 (8.3%). No mutations in the PMS2 gene were reported. Sixty-six co-mutations in 9 cases were found, with TP53 (88.9%), NF1 (44.4 %), ATM (33.3%), and RB1 (33.3%) being the most frequent. No RAS mutations were noted. Survival ranged between 2.8 and 48 months, and patient age varied between 49 and 84 years. There are insufficient and heterogenous data concerning the predictive or prognostic value of mismatch repair-deficient/microsatellite instability status.
Tumour molecular profiling is fundamental in ATC for predictive, prognostic, as well as therapeutic reasons, and analysis of MSI status is strongly suggested because a small subgroup show the MSI signature and might profit from recently approved targeted therapies.
Summary
Extranodal marginal zone lymphoma of mucosa‐associated lymphoid tissue (MALT lymphoma) comprises 7–8% of B‐cell lymphomas and commonly originates from a background of long‐standing chronic ...inflammation. An association with distinct bacteria species has been confirmed for several anatomical sites of MALT lymphoma. For pulmonary MALT lymphoma, however, a clear link with an infectious agent or autoimmune disorder has not yet been reported. Using a 16S rRNA gene–based approach, we have recently identified Achromobacter (Alcaligenes) xylosoxidans in eight of nine cases of pulmonary MALT lymphoma. A. xylosoxidans is a gram‐negative betaproteobacterium with low virulence, but high resistance to antibiotic treatment. To further examine a potential association with A. xylosoxidans, 124 cases of pulmonary MALT lymphoma and 82 control tissues from six European countries were analysed using a specific nested PCR. Although prevalence rates for A. xylosoxidans varied significantly from country to country, they were consistently higher for MALT lymphoma as compared to controls. Overall, 57/124 (46%) pulmonary MALT lymphomas and 15/82 (18%) control tissues were positive for A. xylosoxidans (P = 0·004). Whether the significant association of A. xylosoxidans with pulmonary MALT lymphoma demonstrated in our study points to a potential causal role in the pathogenesis of this lymphoma will require further studies.
Thyroid transcription factor-1 (TTF-1) is a marker of tumors of pulmonary and thyroid origin, and its expression practically excludes diagnosis of Merkel cell carcinoma (MCC). However, TTF-1 ...expression in combined MCC was recently reported. PAX5 is a marker of B-cell origin that is also expressed in most classical MCC cases; however, its expression was not described in combined MCC. The authors decided to evaluate the expression of both these markers in a group of 5 combined MCCs (2 with invasive squamous cell carcinoma, 2 with squamous cell carcinoma in situ, and 1 with basal cell carcinoma). Expression of TTF-1 was found in 4 of 5 cases; in 3 cases, the marker was shown in the MCC component (weakly in 2 cases and strongly in 1 case), whereas the non-MCC component presented TTF-1 expression in 2 cases. A weak-to-moderate immunoreactivity for PAX5 was identified in all cases of the MCC component but in none of the non-MCC component. The results show that the expression of TTF-1 is a frequent finding in combined MCC and can be present in the neuroendocrine component, which differs from the conventional MCC. In contrast, PAX5 expression pattern is similar to that of the classical MCC.
Purpose
SARS‐CoV‐2 vaccines cause acute ipsilateral lymph node swelling in an important proportion of vaccines. Thus far, no malignant lymphadenopathies have been reported in temporal context to ...vaccination in the ipsilateral draining lymph node areas.
Experimental design
Prompted by two cases with unilateral axillary lymphomas that occurred ipsilaterally to prior SARS‐CoV‐2 vaccination, we systematically retrieved all B‐cell non‐Hodgkin lymphomas at two German University Medical Centers diagnosed before and after introduction of SARS‐CoV‐2 vaccines in Germany. Available lymphoma tissue (n=19) was subjected to next‐generation immunosequencing of the IGH locus. Malignant clonotypes were mined in the CoVabDab database and published data sets from 342 uninfected individuals, 55 individuals 28 days after anti‐SARS‐CoV‐2 vaccination and 139 individuals with acute COVID‐19 together encompassing over 1 million CDR3 sequences in total.
Results
Of 313 newly diagnosed cases in the two centers and observation periods, 27 unilateral manifestations in the defined deltoid draining regions were identified. The majority thereof were diffuse large B‐cell lymphomas (18 of 27 cases). Eleven unilateral cases were diagnosed in the era of SARS‐CoV‐2 vaccination and 16 in the control period before introduction of such vaccines. Of the 11 unilateral lymphomas that occurred during the vaccination period, ten had received a SARS‐CoV‐2 vaccine prior to lymphoma diagnosis. These cases were further evaluated. While left‐sided were more frequent than right‐sided lymphomas (19 vs 8 cases), no statistically significant association of vaccination site and laterality of the lymphoma manifestation was found. The unilateral lymphomas showed a normal range of B‐cell receptors typically found in these lymphoma subtypes with no evidence for anti‐SARS‐CoV‐2 sequences in the malignant clonotype.
Conclusions
Together, we found no evidence that the current SARS‐CoV‐2 vaccines could serve as a trigger for lymphomagenesis in the draining lymph node areas of the deltoid region used for vaccination.
Systematical screening including NGS immunosequencing of B‐cell non‐Hodkin lymphomas at two German University Meidcal Ceners diagnosed before and after introduction of SARS‐CoV‐2 vaccines. There was no evidence that the current SARS‐CoV‐2 vaccines could serve as a trigger for lymphomagenesis.
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