We performed comprehensive proteogenomic characterization of small cell lung cancer (SCLC) using paired tumors and adjacent lung tissues from 112 treatment-naive patients who underwent surgical resection. Integrated multi-omics analysis illustrated cancer biology downstream of genetic aberrations and highlighted oncogenic roles of FAT1 mutation, RB1 deletion, and chromosome 5q loss. Two prognostic biomarkers, HMGB3 and CASP10, were identified. Overexpression of HMGB3 promoted SCLC cell migration via transcriptional regulation of cell junction-related genes. Immune landscape characterization revealed an association between ZFHX3 mutation and high immune infiltration and underscored a potential immunosuppressive role of elevated DNA damage response activity via inhibition of the cGAS-STING pathway. Multi-omics clustering identified four subtypes with subtype-specific therapeutic vulnerabilities. Cell line and patient-derived xenograft-based drug tests validated the specific therapeutic responses predicted by multi-omics subtyping. This study provides a valuable resource as well as insights to better understand SCLC biology and improve clinical practice.

Lung squamous cell carcinoma (LUSC) represents a major subtype of lung cancer with limited treatment options. KMT2D is one of the most frequently mutated genes in LUSC (>20%), and yet its role in LUSC oncogenesis remains unknown. Here, we identify KMT2D as a key regulator of LUSC tumorigenesis wherein Kmt2d deletion transforms lung basal cell organoids to LUSC. Kmt2d loss increases activation of receptor tyrosine kinases (RTKs), EGFR and ERBB2, partly through reprogramming the chromatin landscape to repress the expression of protein tyrosine phosphatases. These events provoke a robust elevation in the oncogenic RTK-RAS signaling. Combining SHP2 inhibitor SHP099 and pan-ERBB inhibitor afatinib inhibits lung tumor growth in Kmt2d-deficient LUSC murine models and in patient-derived xenografts (PDXs) harboring KMT2D mutations. Our study identifies KMT2D as a pivotal epigenetic modulator for LUSC oncogenesis and suggests that KMT2D loss renders LUSC therapeutically vulnerable to RTK-RAS inhibition.

Heterogeneity plays an important role in cancer genesis and progression. In this paper, we theoretically and computationally show that the increase of heterogeneity signals prede-terioration during tumor progression by unified random ordinary differential equations (RODEs). Tumor formation results from a systematic change in organisms, and its causality is complex. Het-erogeneity may be one of the key factors under some conditions. Specifically, the interactions between cell populations are modeled by random community matrices in normal tissues, benign tumors, and malignant tumors, and then we prove that the RODEs system describing the cell density of normal tissues or benign tumors becomes unstable as heterogeneity of cell populations or species increases. The increase of heterogeneity is an important signal. Heterogeneity can be viewed as a feature to dis-tinguish benign tumors from malignant tumors under certain circumstances. Furthermore, we show that with the increase of heterogeneity, the divergence speed of the RODEs system becomes faster, which implies that malignant tumors with higher heterogeneity may develop faster and have poorer prognoses. Our theoretical findings can explain some noteworthy phenomena in various datasets in tumor patients and our biological experiments in mice from a mathematical viewpoint. Particularly, clinical data and mutation information from the cancer genome atlas and our experiments in mice revealed that tumors with higher heterogeneity usually show shorter survival time, whereas tumors with lower heterogeneity tend to have better prognosis, which also indicates that heterogeneity can be used as a potential biomarker in future clinical diagnosis. Targeting the heterogeneity may be a potential strategy for the cancer treatment.

Purpose: To evaluate the effectiveness of pancreatic duct stent placement for preventing postoperative pancreatic fistula after pancreaticoduodenectomy.Methods: PubMed, the Cochrane Central Register of Controlled Trials, Embase and ClinicalTrials.gov databases were searched up to February 26, 2022. Studies comparing outcomes following pancreaticoduodenectomy with or without pancreatic duct stents were included. The primary outcome measured was postoperative pancreatic fistula rate, and secondary outcomes were in-hospital mortality rate, reoperation rate, delayed gastric emptying rate and wound infection rate.Results: Seven RCTs involving 847 patients met the inclusion criteria. No statistically significant difference between the stent group and non-stent group was detected in the incidence of postoperative pancreatic fistula (RR = 0.85, 95%CI: 0.57-1.26, P = 0.41), in-hospital mortality, reoperation, delayed gastric emptying rate and wound infection. Subgroup analyses revealed that use of an external stent significantly reduced the incidence of pancreatic fistula (RR = 0.61, 95%CI: 0.43-0.86, P = 0.005).Conclusions: Our preliminary results from this systematic review and meta-analysis revealed that pancreatic duct stents did not reduce the risk of POPF and other complications after pancreaticoduodenectomy compared with no stents. External stents were associated with a reduced POPF rate compared with no stents. Large-scale RCTs are required to assess the effectiveness and assist in clarifying the real role of pancreatic duct stents with respect to the POPF rates after pancreaticoduodenectomy.

Small-cell lung cancer (SCLC) is a recalcitrant cancer characterized by high metastasis. However, the exact cell type contributing to metastasis remains elusive. Using a Rb1 L/L /Trp53 L/L mouse model, we identify the NCAMhiCD44lo/- subpopulation as the SCLC metastasizing cell (SMC), which is progressively transitioned from the non-metastasizing NCAMloCD44hi cell (non-SMC). Integrative chromatin accessibility and gene expression profiling studies reveal the important role of the SWI/SNF complex, and knockout of its central component, Brg1, significantly inhibits such phenotypic transition and metastasis. Mechanistically, TAZ is silenced by the SWI/SNF complex during SCLC malignant progression, and its knockdown promotes SMC transition and metastasis. Importantly, ectopic TAZ expression reversely drives SMC-to-non-SMC transition and alleviates metastasis. Single-cell RNA-sequencing analyses identify SMC as the dominant subpopulation in human SCLC metastasis, and immunostaining data show a positive correlation between TAZ and patient prognosis. These data uncover high SCLC plasticity and identify TAZ as the key molecular switch in orchestrating SCLC phenotypic transition and metastasis.

Small cell lung cancer (SCLC) lacks effective treatments to overcome chemoresistance. Here we established multiple human chemoresistant xenograft models through long-term intermittent chemotherapy, mimicking clinically relevant therapeutic settings. We show that chemoresistant SCLC undergoes metabolic reprogramming relying on the mevalonate (MVA)–geranylgeranyl diphosphate (GGPP) pathway, which can be targeted using clinically approved statins. Mechanistically, statins induce oxidative stress accumulation and apoptosis through the GGPP synthase 1 (GGPS1)–RAB7A–autophagy axis. Statin treatment overcomes both intrinsic and acquired SCLC chemoresistance in vivo across different SCLC PDX models bearing high GGPS1 levels. Moreover, we show that GGPS1 expression is negatively associated with survival in patients with SCLC. Finally, we demonstrate that combined statin and chemotherapy treatment resulted in durable responses in three patients with SCLC who relapsed from first-line chemotherapy. Collectively, these data uncover the MVA–GGPP pathway as a metabolic vulnerability in SCLC and identify statins as a potentially effective treatment to overcome chemoresistance.

Aim The aim was to evaluate the efficacy of transanal drainage tube (TDT) placement for preventing anastomotic leakage after low anterior resection for rectal cancer. Method PubMed, the Cochrane Central Register of Controlled Trials, Embase and databases were searched up to October 2021. Studies comparing outcomes following low anterior resection with or without TDT were included. The primary outcomes measured were anastomotic leakage rate, reoperation rate and anastomotic bleed rate. Results Three randomized controlled trials (RCTs) and 16 observational studies (prospective or retrospective) involving 4560 patients satisfied the basic inclusion criteria. In RCTs, a TDT was associated with no statistically significant differences in anastomotic leakage (OR = 0.67, 95% CI 0.42-1.05, P = 0.08), reduction in reoperation (OR = 0.11, 95% CI 0.03-0.51, P = 0.004) and increased anastomotic bleeding rate (OR = 2.36, 95% CI 1.11-5.01, P = 0.03). In observational studies, a TDT was associated with significant reduction in anastomotic leak (OR = 0.44, 95% CI 0.30-0.64, P < 0.0001) and reoperation (OR = 0.47, 95% CI 0.33-0.69, P < 0.0001), with no statistically significant differences in anastomotic bleeding (OR = 1.30, 95% CI 0.20-8.30, P = 0.78). Conclusion In RCTs, a TDT for rectal cancer was correlated with no detectable differences in anastomotic leakage and with an increased risk of anastomotic bleeding. In observational studies, a TDT was correlated with reduction in anastomotic leakage and no detectable differences in anastomotic bleeding. Both RCTs and observational studies demonstrated a comparable reduction in reoperation rate with TDT. These data in aggregate indicated that TDTs may not show superiority but emphasized differences between RCT and observational data.

Small cell lung cancer (SCLC) is the most aggressive lung cancer with high heterogeneity.Mouse SCLC cells derived from the Rb 1L/L/Trp53L/L (RP) autochthonous mouse model grew as adhesion or suspension in cell culture,and the adhesion cells are defined as non-neuroendocrine (non-NE) SCLC cells.Here,we uncover the heterogenous subpopulations within the non-NE cells and referred to them as mesenchymal-like (Mes) and epithelial-like (Epi) SCLC cells.The Mes cells have increased capability to form colonies in soft agar and harbored stronger metastatic capability in vivo when compared with the Epi cells.Gene Set Enrichment Analysis reveals that the transforming growth factor (TGF)-β signaling is enriched in the Mes cells.Importantly,inhibition of the TGF-β signaling through ectopic expression of dominant-negative Tgfbr2(Tgfbr2-DN) or treatment with Tgfbr1 inhibitor SD-208 consistently abrogates tumor metastasis in nude mouse allograft assays.Moreover,genetic deletion of Tgfbr2 or Smad4,the key components of the TGF-β signaling pathway,dramatically attenuates SCLC metastasis in the RP autochthonous mouse model.Collectively,our results uncover the high heterogeneity in non-NE SCLC cells and highlight an important role of TGF-β signaling in promoting SCLC metastasis.

Abstract Small cell lung cancer (SCLC) is highly invasive and lethal. Genomic studies are beginning to characterize its genetic determinants and heterogeneity. Here we performed RNA-Seq and whoe exome sequencing (WES) in 19 Chinese SCLC clinical tumor specimens. Integration with other two public cohorts (n = 129 for RNA-seq, n = 171 for WES), we carried out gene co-expression network analysis and classified into four subgroups: ASCL1-high, NEUROD1-high, a novel variant subtype with CCSP/CC10-high, and a fourth subtype with high expression of NOTCH family and inflammatory genes. We further found that this fourth subtype was characterized by overexpression of immune-related pathways and immunosuppressive factors, referred to as immune subtype. In addition to transcriptomic signatures, specific genomic alterations were also significantly enriched in each subtype. We successfully built a machine learning model to predict the subtypes of newly coming specimens based on transcriptomic data. In particular, we found that POU2F3 protein was effective in distinguishing immunotherapy patients, i.e. the immune subtype, which was further validated by an independent data of chemo-resistant patients received 2nd -line immunotherapy. Collectively, our work systematically studied the transcriptomic and genomic heterogeneity of SCLC, and characterized an immune subtype that displayed features of sensitivity to immune checkpoint-based therapies.

Metastasis is the dominant cause of patient death in small-cell lung cancer (SCLC), and a better understanding of the molecular mechanisms underlying SCLC metastasis may potentially improve clinical treatment. Through genome-scale screening for key regulators of mouse Rb1(-/-) Trp53(-/-) SCLC metastasis using the pooled CRISPR/Cas9 library, we identified Cullin5 (CUL5) and suppressor of cytokine signaling 3 (SOCS3), two components of the Cullin-RING E3 ubiquitin ligase complex, as top candidates. Mechanistically, the deficiency of CUL5 or SOCS3 disrupted the functional formation of the E3 ligase complex and prevented the degradation of integrin beta 1, which stabilized integrin beta 1 and activated downstream focal adhesion kinase/SRC (FAK/SRC) signaling and eventually drove SCLC metastasis. Low expression levels of CUL5 and SOCS3 were significantly associated with high integrin beta 1 levels and poor prognosis in a large cohort of 128 clinical patients with SCLC. Moreover, the CUL5-deficient SCLCs were vulnerable to the treatment of the FDA-approved SRC inhibitor dasatinib. Collectively, this work identifies the essential role of CUL5- and SOCS3-mediated integrin beta 1 turnover in controlling SCLC metastasis, which might have therapeutic implications.

Drug resistance is a significant hindrance to effective cancer treatment. Although resistance mechanisms of epidermal growth factor receptor (EGFR) mutant cancer cells to lethal EGFR tyrosine kinase inhibitors (TKI) treatment have been investigated intensively, how cancer cells orchestrate adaptive response under sublethal drug challenge remains largely unknown. Here, we find that 2-h sublethal TKI treatment elicits a transient drug-tolerant state in EGFR mutant lung cancer cells. Continuous sublethal treatment reinforces this tolerance and eventually establishes long-term TKI resistance. This adaptive process involves H3K9 demethylation-mediated upregulation of branched-chain amino acid aminotransferase 1 (BCAT1) and subsequent metabolic reprogramming, which promotes TKI resistance through attenuating reactive oxygen species (ROS) accumulation. Combination treatment with TKI- and ROS-inducing reagents overcomes this drug resistance in preclinical mouse models. Clinical information analyses support the correlation of BCAT1 expression with the EGFR TKI response. Our findings reveal the importance of BCAT1-engaged metabolism reprogramming in TKI resistance in lung cancer.

Small cell lung carcinoma (SCLC) is one of the deadliest cancer types, with a 5-year survival rate less than 10%. Kdm1a/Lsd1 has recently been implicated as a potential therapeutic target for SCLC. However, the underlying molecular mechanism by which Kdm1a promotes the oncogenesis of SCLC has not been fully understood. Kdm1a is significantly elevated in most human SCLC specimens, whereas Rest, a tumor suppressor and neuronal repressive transcriptional factor, is typically inactivated. Knock-out of Kdm1a (Kdm1a-KO) in mouse SCLC cell lines resulted in the suppression of cell growth and soft agar colony formation. RNA-Seq analysis of the Kdm1a-KO cells revealed significant repression of a program of neuroendocrine signature genes, and conversely, a significant upregulation of a network of genes capable of inhibiting tumor cell growth. Rest was identified among the top 10 upregulated genes in Kdm1a-KO cells. The treatment of the SCLC cells with Kdm1a demethylase inhibitors resulted in a dramatic up-regulation of Rest similar to the extent of that in Kdm1a-KO cells. Importantly, accompanying the restored expression of the SCLC signature genes, knock-out of Rest in Kdm1a-KO cells rescued the restricted cell growth and soft agar colony formation. Taken together, these novel findings show that Kdm1a is a key transcriptional repressor of Rest, and that suppression of SCLC progression by the targeted inhibition of Kdm1a depends on the reactivation of Rest, suggesting a new strategy for effective SCLC treatment by targeting the Kdm1a/Rest molecular pathway.

Lung squamous cell carcinoma (SCC) is one of the major subtypes of lung cancer. Our current knowledge of oncogenic drivers in this specific subtype of lung cancer is largely limited compared with lung adenocarcinoma (ADC). Through exon array analyses, molecular analyses and functional studies, we here identify the TRA2B-DNAH5 fusion as a novel oncogenic driver in lung SCC. We found that this gene fusion occurs exclusively in lung SCC (3.1%, 5/163), but not in lung ADC (0/119). Through mechanistic studies, we further revealed that this TRA2B-DNAH5 fusion promotes lung SCC malignant progression through regulating a SIRT6-ERK1/2-MMP1 signaling axis. We show that inhibition of ERK1/2 activation using selumetinib efficiently inhibits the growth of lung SCC with TRA2B-DNAH5 fusion expression. These findings improve our current knowledge of oncogenic drivers in lung SCC and provide a potential therapeutic strategy for lung SCC patients with TRA2B-DNAH5 fusion.

Metastasis is the major cause for high mortality of lung cancer with the underlying mechanisms poorly understood. The scaffolding protein neural precursor cell expressed, developmentally down-regulated 9 (NEDD9) has been identified as a pro-metastasis gene in several types of cancers including melanoma and breast cancer. However, the exact role and related mechanism of NEDD9 in regulating lung cancer metastasis still remain largely unknown. Here, we demonstrate that NEDD9 knockdown significantly inhibits migration, invasion and metastasis of lung cancer cells in vitro and in vivo. The pro-metastasis role of Nedd9 in lung cancer is further supported by studies in mice models of spontaneous cancer metastasis. Moreover, we find that NEDD9 promotes lung cancer cell migration and invasion through the induction of epithelial-mesenchymal transition (EMT) potentially via focal adhesion kinase activation. More importantly, NEDD9 expression inversely correlates with E-cadherin expression in human lung cancer specimens, consistent with the findings from in vitro studies. Taken together, this study highlights that NEDD9 is an important mediator promotes lung cancer metastasis via EMT.