Challenges in the treatment of small cell lung cancer in the era of immunotherapy and molecular classification

Dynamic evolution and antitumor mechanisms of CXCR6+CD8+ T cells in small cell lung cancer treated with low-dose radiotherapy and immunotherapy

BACKGROUND

Patients with small-cell lung cancer (SCLC) have the poor prognosis. Current research suggested that low-dose radiotherapy (LDRT) combined with immunotherapy can enhance the immunogenicity of tumor cells, thereby improving antigen presentation and promoting the intratumoral infiltration of CD8+ T cells, which significantly extends the survival of patients. However, the change trajectory of T cells, and the mechanisms underlying the promotion of intratumoral infiltration of CD8+ T cells, and the enhancement of their cytotoxic functions remain to be elucidated.

METHODS

To delineate the dynamic changes of T cells, we collected tumors from Kaede tumor-bearing mice that had undergone radioimmunotherapy. Using flow cytometry, we sorted intratumoral-infiltrating immune cells, which were required for single-cell RNA sequencing, at various time points (Kaede Red: derived from tumor-draining lymph node [TDLN]). The results obtained from the sequencing analysis were further validated through experiments, such as flow cytometry, immunofluorescence, and analysis of clinical cohort data.

RESULTS

Here, we observed stem-like T cells migrating from the TDLN to the tumor site and differentiating into effector phenotypes within the tumor. Dendritic cells (DCs) are the key cluster that induces the differentiation of stem-like T cell into effector phenotypes. Moreover, SCLC patients with a high infiltration of tumor-specific CXCR6+CD8+ T cells exhibited a supportive TME and longer survival time (P < 0.001).

CONCLUSIONS

This study delineates the change trajectory of CD8+ T cells, identifies the crucial role of DCs in T cell differentiation, and highlights the significance of tumor-specific CXCR6+CD8+ T cells in anti-tumor immunity. Future therapeutic strategies for SCLC could focus on enhancing the infiltration of activated DCs and CXCR6+CD8+ T cells within the tumor microenvironment to improve treatment efficacy.

Current and future therapies for small cell lung carcinoma

Small cell lung cancer (SCLC) is an aggressive malignancy characterized by rapid proliferation and high metastatic potential. It is characterized by universal inactivation of and RB1, overexpression of the MYC family and dysregulation of multiple oncogenic signaling pathways. Among different patients, SCLCs are similar at the genetic level but exhibit significant heterogeneity at the molecular level. The classification of SCLC has evolved from a simple neuroendocrine (NE)/non-neuroendocrine (non-NE) classification system to a transcription factor-based molecular subtype system; lineage plasticity adds further complexity and poses challenges for therapeutic development. While SCLC is initially sensitive to platinum-based chemotherapy, resistance develops rapidly, leading to a dismal prognosis. Various antibodies, including PD-1/PD-L1 inhibitors and antibody‒drug conjugates, have been introduced into clinical practice or are being evaluated in clinical trials. However, their therapeutic benefits for SCLC patients remain limited. This review summarizes SCLC carcinogenic mechanisms, tumor heterogeneity, and the immune microenvironment of SCLC, with a focus on recent advances in metastasis and resistance mechanisms. Additionally, the corresponding clinical progress in tackling these challenges is discussed.

[Molecular characterization of lung cancers: up-date and recommendations]

Molecular testing of non-small cell lung cancers has become mandatory at all stages of the disease. National and international recommendations for molecular testing are up-dated regularly. In this review, we will summarize diagnostic approaches focusing on targetable oncogenic alterations (mutations, gene rearrangements) and we will indicate the limits currently associated with sample types and sequencing technologies. Biomarkers that have not showed routine clinical utility will not be presented here.

Real-world evidence in extensive disease small cell lung cancer: The missing piece of the puzzle

Small cell lung cancer (SCLC) is a highly aggressive disease, often diagnosed at an advanced stage and with limited treatment options. In recent years, immunotherapy has been approved in combination with chemotherapy in the first line setting of extensive stage disease (ES-SCLC). However, only 10-15 % of patients with ES-SCLC treated with chemoimmunotherapy (CT-IO) experience a long-term benefit. In addition, patients are often clinically frail due to advanced age, comorbidities, and disease-related symptoms, making SCLC a challenging condition. Real-world evidence (RWE) becomes particularly valuable in this scenario, not only to confirm the results of pivotal trials, but also to evaluate the outcomes of CT-IO in populations that are generally excluded from clinical trials. RWE could also define the role of integrative treatments such as thoracic consolidation radiotherapy and prophylactic cranial irradiation, which are used in selected patients in the clinical practice but were scarcely applied in pivotal trials. In this review, we focused on RWE in ES-SCLC, with the aim of improving clinical decision making. Notably, real-world data have largely confirmed the efficacy and safety of CT-IO observed in pivotal clinical trials, with a possible benefit even in more fragile patients. However, these studies also highlight that a significant proportion of the ES-SCLC population remains untreated due to poor clinical conditions.

Small cell lung cancer unveiled: Exploring the untapped resource of circulating tumor cells-derived organoids

Small cell lung cancer (SCLC) remains a challenge in oncology due to its aggressive behavior and dismal prognosis. Despite advances in treatments, novel strategies are urgently needed. Enter liquid biopsy-a game-changer in SCLC management. This revolutionary non-invasive approach allows for the analysis of circulating tumor cells (CTCs), offering insights into tumor behavior and treatment responses. Our review focuses on a groundbreaking frontier: harnessing CTCs to create three-dimensional (3D) organoid models. These models, derived from CTCs that break away from the primary tumor or metastatic locations, hold immense potential for revolutionizing cancer research, especially in SCLC. We explore the essential conditions for successfully establishing CTC-derived organoids-a transformative approach with profound implications for personalized medicine. Our evaluation spans diverse isolation techniques, shedding light on their advantages and limitations. Furthermore, we uncover the critical factors governing the cultivation of 3D organoids from CTCs, meticulously mimicking the tumor microenvironment. This review comprehensively elucidates the molecular characterization of these organoids, showcasing their potential in identifying treatment targets and predicting responses. In essence, our review amalgamates cutting-edge methodologies for isolating CTCs, establishing transformative CTC-derived organoids, and characterizing their molecular landscape. This represents a promising frontier for advancing personalized medicine in the complex realm of SCLC management and holds significant implications for translational research.

Prior antibiotics, proton pump inhibitors, and probiotics in patients with extensive stage small cell lung cancer treated with immune checkpoint blockade: A post-hoc analysis of the phase I/III IMpower 133 trial

The potential impact of concomitant medications such as systemic antibiotics, proton pump inhibitors (PPIs), and probiotics in patients with extensive-stage small cell lung cancer (ES-SCLC) receiving first-line chemo-immunotherapy combinations remains unclear. We ran a post hoc analysis of the IMpower133 phase I/III trial, which randomized patients with ES-SCLC to receive carboplatin/etoposide with either atezolizumab or placebo for 4 cycles, followed by maintenance therapy. We included any systemic antibiotic/probiotic exposure within 42 days prior to treatment initiation and any PPIs treatment within 30 days prior to treatment initiation. We explored the potential prognostic impact of antibiotics, PPIs and probiotics across the atezolizumab/chemotherapy and placebo/chemotherapy arms including the multivariable interaction term between the treatment modality and antibiotics/PPIs/probiotics. The analysis included 198 patients in the atezolizumab/chemotherapy arm and 195 in the placebo/chemotherapy arm. Baseline clinic-pathologic features were well balanced between the two cohorts, with 17 (8.6%) and 14 (7.2%) patients on antibiotics, 43 (21.7%) and 55 (28.2%) on PPIs, and 3 (1.5%) and 5 (2.6%) on probiotics among the atezolizumab/chemotherapy and placebo/chemotherapy cohorts, respectively. Exposure to antibiotics, PPIs, or probiotics was not associated with overall survival or progression free survival in either cohort. Furthermore, interaction terms between these medications and treatment modalities were not statistically significant. Baseline use of antibiotics, PPIs or probiotics did not influence clinical outcomes in patients with ES-SCLC treated with first-line atezolizumab/placebo plus chemotherapy, suggesting that they may not have a notable impact on clinical outcomes and could be considered for use in this patient population when necessary.

A549 Alveolar Carcinoma Spheroids as a Cytotoxicity Platform for Carboxyl- and Amine-Polyethylene Glycol Gold Nanoparticles

Gold nanoparticles (AuNPs) present with unique physicochemical features and potential for functionalization as anticancer agents. Three-dimensional spheroid models can be used to afford greater tissue representation due to their heterogeneous phenotype and complex molecular architecture. This study developed an A549 alveolar carcinoma spheroid model for cytotoxicity assessment and mechanistic evaluation of functionalized AuNPs. A549 spheroids were generated using an agarose micro-mold and were characterized (morphology, acid phosphatase activity, protein content) over 21 culturing days. The 72-h cytotoxicity of carboxyl-polyethylene glycol- (PCOOH-) and amine-polyethylene glycol- (PNH2-) functionalized AuNPs against Day 7 spheroids was assessed by determining spheroid morphology, acid phosphatase activity, protein content, caspase-3/7 activity, and cell cycle kinetics. Spheroids remained stable over the experimental period. Although the A549 spheroids' volume increased while remaining viable over the culturing period, structural integrity decreased from Day 14 onwards. The PCOOH-AuNPs lacked cytotoxicity at a maximum concentration of 1.2 × 1012 nanoparticles/mL with no prominent alteration to the cellular processes investigated, while the PNH2-AuNPs (at a maximum of 4.5 × 1012 nanoparticles/mL) displayed dose- and time-dependent cytotoxicity with associated loss of spheroid compactness, debris formation, DNA fragmentation, and a 75% reduction in acid phosphatase activity. Differentiation between cytotoxic and non-cytotoxic AuNPs was achieved, with preliminary elucidation of cytotoxicity endpoints. The PNH2-AuNPs promote cytotoxicity by modulating cellular kinetics while destabilizing the spheroid ultrastructure. The model serves as a proficient platform for more in-depth elucidation of NP cytotoxicity at the preclinical investigation phase.

A review of the immunomodulatory properties of mesenchymal stem cells and their derived extracellular vesicles in small-cell and non-small-cell lung cancer cells

Among the most challenging diseases to treat is lung cancer (LC). While immunotherapy has a checkered history, it has lately shown great promise in the treatment of LC, and interest in this promising new approach is on the rise around the globe. Immunotherapy using mesenchymal stem cells (MSCs) is gaining popularity. Regenerative medicine, cell therapy, and immune modulation are three areas that have shown significant interest in MSCs. More than that, MSCs have recently attracted attention as potential anti-cancer drug delivery vehicles due to their inherent ability to go home to tumor locations. Making MSCs a double-edged sword in the fight against neoplastic illnesses, they are also known to impart pro-oncogenic properties. Additionally, multiple studies have proposed extracellular vesicles (EVs) secreted by MSCs as a potential therapeutic agent or method for delivering anti-cancer drugs. However, there has been conflicting evidence regarding the impact of MSCs or MSC-EV on the behavior of cancer cells, and the exact mechanism for this effect is still unknown. Our research has focused on MSCs and their key characteristics, such as their immunomodulatory capabilities for cancer therapy. Our research has also explored the potential of MSCs and their derivatives to treat small-cell and non-small-cell lung cancers (NSCLC and SCLC, respectively) by leveraging MSCs' immunomodulatory characteristics. At the end of this article, we covered the pros and cons of this therapy procedure, as well as what researchers want to do in the future to make it more suitable for clinical application in LC treatment.

Disseminated tumor cells in bone marrow as predictive classifiers for small cell lung cancer patients

Background

Small cell lung cancer (SCLC) is a highly aggressive disease characterized by early metastasis. Aneuploid CD31- disseminated tumor cells (DTCs) and CD31+ disseminated tumor endothelial cells (DTECs) residing in the bone marrow are generally considered as the initiators of metastatic process. However, the clinical significance of DTCs and DTECs in SCLC remains poorly understood. The aim of this study is to investigate the clinical implications of diverse subtypes of highly heterogeneous DTCs and DTECs in SCLC patients.

Methods

Subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) was applied to enrich and perform comprehensive morphologic, karyotypic, and phenotypic characterization of aneuploid DTCs and DTECs in 30 patients. Additionally, co-detection of circulating tumor cells (CTCs) and circulating tumor endothelial cells (CTECs) was conducted on 24 of the enrolled patients. Proof-of-concept of the whole exon sequencings (WES) on precisely selected different subtypes of CTCs or DTCs, longitudinally detected from a representative case with pathologically confirmed bone marrow metastasis, was validated to feasibly reveal genetic mutations in these cells.

Results

DTCs, DTECs and their subtypes were readily detectable in SCLC patients. Comparative analysis revealed that the number of DTCs and DTECs was significantly higher than that of their corresponding CTCs and CTECs (P < 0.001 for both). Positive detection of disseminated tumor microemboli (DTM) or disseminated tumor endothelial microemboli (DTEM) was associated with inferior survival outcomes (P = 0.046 and P = 0.048). Patients with EpCAM+ DTCs detectable displayed significantly lower disease control rate (DCR) (16.67% vs 73.33%, P = 0.019), reduced median progression-free survival (mPFS) and median overall survival (mOS) compared with those with EpCAM- DTCs (P = 0.028 and P = 0.002, respectively). WES analysis indicated that post-treatment DTCs isolated from bone marrow at the time of disease progression shared more homologous somatic gene mutations with pre-treatment CTCs compared with post-treatment CTCs.

Conclusions

Our findings suggest that bone marrow sampling and characterization of DTC subtypes provided a valuable tool for predicting treatment response and the prognosis in SCLC. Moreover, DTCs inherit a greater amount of homologous somatic information from pre-treatment CTCs, indicating their potential role in disease progression and treatment resistance.

Navigating the Complexity of Resistance in Lung Cancer Therapy: Mechanisms, Organoid Models, and Strategies for Overcoming Treatment Failure

Background: The persistence of chemotherapy-resistant and dormant cancer cells remains a critical challenge in the treatment of lung cancer. Objectives: This review focuses on non-small cell lung cancer and small cell lung cancer, examining the complex mechanisms that drive treatment resistance. Methods: This review analyzed current studies on chemotherapy resistance in NSCLC and SCLC, focusing on tumor microenvironment, genetic mutations, cancer cell heterogeneity, and emerging therapies. Results: Conventional chemotherapy and targeted therapies, such as tyrosine kinase inhibitors, often fail due to factors including the tumor microenvironment, genetic mutations, and cancer cell heterogeneity. Dormant cancer cells, which can remain undetected in a quiescent state for extended periods, pose a significant risk of recurrence upon reactivation. These cells, along with intrinsic resistance mechanisms, greatly complicate treatment efforts. Understanding these pathways is crucial for the development of more effective therapies. Emerging strategies, including combination therapies that target multiple pathways, are under investigation to improve treatment outcomes. Innovative approaches, such as antibody-drug conjugates and targeted protein degradation, offer promising solutions by directly delivering cytotoxic agents to cancer cells or degrading proteins that are essential for cancer survival. The lung cancer organoid model shows substantial promise to advance both research and clinical applications in this field, enhancing the ability to study resistance mechanisms and develop personalized treatments. The integration of current research underscores the need for continuous innovation in treatment modalities. Conclusions: Personalized strategies that combine novel therapies with an in-depth understanding of tumor biology are essential to overcome the challenges posed by treatment-resistant and dormant cancer cells in lung cancer. A multifaceted approach has the potential to significantly improve patient outcomes.

Patients with Extensive-Stage Small Cell Lung Cancer Harboring Less Than 4 Metastatic Sites May Benefit from Immune Checkpoint Inhibitor Rechallenge by Reshaping Tumor Microenvironment

Background

Immune checkpoint inhibitors (ICIs) has prolonged survival in patients with extensive-stage small cell lung cancer (ES-SCLC) as first-line treatment. However, whether ICI rechallenge could bring survival benefit to patients with ES-SCLC following its failure as first-line treatment remains unknown. Therefore, we aim to address the issue and identify the cohort of patients that may derive such benefit.

Methods

Patients with ES-SCLC from both the IMpower133 study and Shandong Cancer Hospital and Institute (shanzhong cohort) who failed first-line ICI were included. Kaplan Meier analysis was performed to compare overall survival (OS). Both univariate and multivariate Cox regression analyses were conducted to identify factors affecting survival. Tumor immune cell infiltration was evaluated by the CIBERSORT algorithm and detected by multiplex immunofluorescence (mIF).

Results

A total of 125 ES-SCLC patients undergoing atezolizumab and 161 patients undergoing ICI as first-line treatment were recruited from IMpower133 and shanzhong cohort. Those receiving ICI rechallenge had a longer OS than those without in IMpower133 (P = 0.08) and shanzhong cohort (P = 0.013). In IMpower133 cohort, subgroup analyses found that patients with <4 metastatic sites derived more survival benefit from atezolizumab (P = 0.008). For patients with ES-SCLC harboring <4 metastatic sites, there was significant OS difference between atezolizumab versus non-atezolizumab as retreatment (P = 0.036). Moreover, for ES-SCLC patients with <4 metastatic sites, atezolizumab improved survival compared with non-atezolizumab (hazard ratio [HR]: 0.457; 95% CI: 0.256-0.817; P = 0.008). These findings were confirmed in shanzhong cohort. Those harboring <4 metastatic sites had fewer M2 macrophage and more CD4 naïve T cells infiltration, which was further confirmed by mIF of ES-SCLC samples from shanzhong cohort.

Conclusion

Our study provides rationale for ICI rechallenge among ES-SCLC patients with <4 metastatic sites, suggesting beneficial outcome by reshaping TME.

Durvalumab after Chemoradiotherapy in Limited-Stage Small-Cell Lung Cancer

BACKGROUND

Adjuvant therapy with durvalumab, with or without tremelimumab, may have efficacy in patients with limited-stage small-cell lung cancer who do not have disease progression after standard concurrent platinum-based chemoradiotherapy.

METHODS

In a phase 3, double-blind, randomized, placebo-controlled trial, we assigned patients to receive durvalumab at a dose of 1500 mg, durvalumab (1500 mg) plus tremelimumab at a dose of 75 mg (four doses only), or placebo every 4 weeks for up to 24 months. Randomization was stratified according to disease stage (I or II vs. III) and receipt of prophylactic cranial irradiation (yes vs. no). Results of the first planned interim analysis of the two primary end points of overall survival and progression-free survival (assessed on the basis of blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1) with durvalumab as compared with placebo (data cutoff date, January 15, 2024) are reported; results in the durvalumab-tremelimumab group remain blinded.

RESULTS

A total of 264 patients were assigned to the durvalumab group, 200 to the durvalumab-tremelimumab group, and 266 to the placebo group. Durvalumab therapy led to significantly longer overall survival than placebo (median, 55.9 months [95% confidence interval {CI}, 37.3 to not reached] vs. 33.4 months [95% CI, 25.5 to 39.9]; hazard ratio for death, 0.73; 98.321% CI, 0.54 to 0.98; P = 0.01), as well as to significantly longer progression-free survival (median 16.6 months [95% CI, 10.2 to 28.2] vs. 9.2 months [95% CI, 7.4 to 12.9]; hazard ratio for progression or death, 0.76; 97.195% CI, 0.59 to 0.98; P = 0.02). The incidence of adverse events with a maximum grade of 3 or 4 was 24.4% among patients receiving durvalumab and 24.2% among patients receiving placebo; adverse events led to discontinuation in 16.4% and 10.6% of the patients, respectively, and led to death in 2.7% and 1.9%. Pneumonitis or radiation pneumonitis with a maximum grade of 3 or 4 occurred in 3.1% of the patients in the durvalumab group and in 2.6% of those in the placebo group.

CONCLUSIONS

Adjuvant therapy with durvalumab led to significantly longer overall survival and progression-free survival than placebo among patients with limited-stage small-cell lung cancer. (Funded by AstraZeneca; ADRIATIC ClinicalTrials.gov number, NCT03703297.).

EBV-positive small cell neuroendocrine carcinoma of nasopharynx as a probably unique subtype of neuroendocrine carcinoma: a clinicopathologic study of three cases and literature review

BACKGROUND

There is currently scarcity of information on small cell neuroendocrine carcinoma of the nasopharynx (SCNEC-nasopharynx). It is believed that this type of cancer is not associated with Epstein-Barr virus (EBV) infection and is indistinguishable from classic SCNEC occurring in other organs.

MATERIALS AND METHODS

Herein we provided 3 cases of nasopharyngeal mass in our hospital, two males and one female. On admission, these patients were considered nasopharyngeal carcinoma with lymph node metastasis, and one of them had liver metastasis. The nasopharyngeal mucosal tissues were biopsied for pathological examination including immunohistochemistry and in situ hybridization. PubMed database was searched for articles about SCNEC-nasopharynx published up to April 2024 in any language.

RESULT

The 3 cases had similar histological features of SCNEC in other organs but differed in rich- tumor-infiltrating lymphocytes (TILs). All of them stained for pancytokeratin (panCK) and epidermal growth factor receptor (EGFR). Case 1 and Case 2 diffusely expressed insulinoma-associated protein 1(INSM-1) and synaptophysin (Syn), Case 3 strongly stained for CD56 and Syn. Immunostaining of all 3 cases for p40, p63, TTF-1, CK20, S-100 and NUT showed negative. BRG-1, INI-1 and Rb were retained. And p53 all showed wild-type expression. The Ki-67 labeling indiced of case 1, 2, and 3 were 80%, 90%, and 80%, respectively. In situ hybridization showed strong and uniform nuclear positivity of EBV-encoded small RNAs (EBER) in the neoplastic cells of 3 cases.

CONCLUSION

EBV-positive SCNEC-nasopharynx was exactly rare. The origin of this tumor is still controversial. It may originate from EBV-infected mucosal epithelium like nasopharyngeal carcinoma. Based on our cases and relevant literature, we found EBV-positive SCNEC-nasopharynx as a probably site-specific subtype of SCNEC with differing pathogenetic mechanism. The subtype not only virus positivity but also that it was associated with TILs and did not show p53 or Rb alterations by immunohistochemistry. It may be more responsive to treatment and have a better prognosis than classic SCNEC. We will continue to follow-up these patients and collect additional cases to further understand the unique biology of this rare solid tumor.

Efficacy and safety of novel immune checkpoint inhibitor-based combinations versus chemotherapy as first-line treatment for patients with extensive-stage small cell lung cancer: A network meta-analysis

BACKGROUND

Patients with extensive-stage small cell lung cancer (ES-SCLC) have an exceptionally poor prognosis and immune checkpoint inhibitors (ICIs) combined with etoposide-platinum is recommended as standard first-line therapy. However, which combination pattern is the best still remains unknown. This network meta-analysis was performed to compare the efficacy and safety of currently available patterns including an antiangiogenic agent containing regimen and probed into the most appropriate therapy for patients.

METHODS

Hazard ratios (HRs) and odds ratios (ORs) were generated using R software. The outcomes of overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse events of grade 3 or higher (grade ≥ 3 adverse events [AEs]) were analyzed.

RESULTS

A total of 10 randomized controlled trials (RCTs) involving 5544 patients were included for analysis. Drug combination patterns included adebrelimab, atezolizumab, durvalumab, durvalumab plus tremelimumab, ipilimumab, pembrolizumab, serplulimab, benmelstobart plus anlotinib, tislelizumab, tiragolumab plus atezolizumab and toripalimab in combination with chemotherapy. The novel antiangiogenic agent containing regimen benmelstobart + anlotinib + chemotherapy showed the highest possibility to present the best PFS and OS versus chemotherapy. Compared with ICI plus chemotherapy, it also achieved significantly better PFS and presented a tendency of OS benefit. As for safety and toxicity, patients treated with benmelstobart + anlotinib + chemotherapy and durvalumab + tremelimumab + chemotherapy suffered a higher likelihood of more grade ≥ 3 AEs without unexpected AEs.

CONCLUSION

PD-1/PD-L1 inhibitors-based combinations are associated with significant improvement in both PFS and OS for treatment-naïve ES-SCLC patients. Benmelstobart plus anlotinib with chemotherapy (CT) yielded better survival benefit versus CT alone or other ICIs + CT with caution for more adverse effects along with the addition of an antiangiogenic agent.

Abnormal expression of Krüppel-like transcription factors and their potential values in lung cancer

Lung cancer still is one of the most common malignancy tumors in the world. However, the mechanisms of its occurrence and development have not been fully elucidated. Zinc finger protein family (ZNFs) is the largest transcription factor family in human genome. Recently, the more and more basic and clinical evidences have confirmed that ZNFs/Krüppel-like factors (KLFs) refer to a group of conserved zinc finger-containing transcription factors that are involved in lung cancer progression, with the functions of promotion, inhibition, dual roles and unknown classifications. Based on the recent literature, some of the oncogenic KLFs are promising molecular biomarkers for diagnosis, prognosis or therapeutic targets of lung cancer. Interestingly, a novel computational approach has been proposed by using machine learning on features calculated from primary sequences, the XGBoost-based model with accuracy of 96.4 % is efficient in identifying KLF proteins. This paper reviews the recent some progresses of the oncogenic KLFs with their potential values for diagnosis, prognosis and molecular target in lung cancer.

Small cells - big issues: biological implications and preclinical advancements in small cell lung cancer

Current treatment guidelines refer to small cell lung cancer (SCLC), one of the deadliest human malignancies, as a homogeneous disease. Accordingly, SCLC therapy comprises chemoradiation with or without immunotherapy. Meanwhile, recent studies have made significant advances in subclassifying SCLC based on the elevated expression of the transcription factors ASCL1, NEUROD1, and POU2F3, as well as on certain inflammatory characteristics. The role of the transcription regulator YAP1 in defining a unique SCLC subset remains to be established. Although preclinical analyses have described numerous subtype-specific characteristics and vulnerabilities, the so far non-existing clinical subtype distinction may be a contributor to negative clinical trial outcomes. This comprehensive review aims to provide a framework for the development of novel personalized therapeutic approaches by compiling the most recent discoveries achieved by preclinical SCLC research. We highlight the challenges faced due to limited access to patient material as well as the advances accomplished by implementing state-of-the-art models and methodologies.

Rictor-A Mediator of Progression and Metastasis in Lung Cancer

Lung carcinoma is one of the most common cancer types for both men and women. Despite recent breakthroughs in targeted therapy and immunotherapy, it is characterized by a high metastatic rate, which can significantly affect quality of life and prognosis. Rictor (encoded by the RICTOR gene) is known as a scaffold protein for the multiprotein complex mTORC2. Among its diverse roles in regulating essential cellular functions, mTORC2 also facilitates epithelial-mesenchymal transition and metastasis formation. Amplification of the RICTOR gene and subsequent overexpression of the Rictor protein can result in the activation of mTORC2, which promotes cell survival and migration. Based on recent studies, RICTOR amplification or Rictor overexpression can serve as a marker for mTORC2 activation, which in turn provides a promising druggable target. Although selective inhibitors of Rictor and the Rictor-mTOR association are only in a preclinical phase, they seem to be potent novel approaches to reduce tumor cell migration and metastasis formation. Here, we summarize recent advances that support an important role for Rictor and mTORC2 as potential therapeutic targets in the treatment of lung cancer. This is a traditional (narrative) review based on Pubmed and Google Scholar searches for the following keywords: Rictor, RICTOR amplification, mTORC2, Rictor complexes, lung cancer, metastasis, progression, mTOR inhibitors.

Longitudinal detection of subcategorized CD44v6+ CTCs and circulating tumor endothelial cells (CTECs) enables novel clinical stratification and improves prognostic prediction of small cell lung cancer: A prospective, multi-center study

Current management of small cell lung cancer (SCLC) remains challenging. Effective biomarkers are needed to subdivide patients presenting distinct treatment response and clinical outcomes. An understanding of heterogeneous phenotypes of aneuploid CD31- circulating tumor cells (CTCs) and CD31+ circulating tumor endothelial cells (CTECs) may provide novel insights in the clinical management of SCLC. In the present translational and prospective study, increased cancer metastasis-related cell proliferation and motility, accompanied with up-regulated mesenchymal marker vimentin but down-regulated epithelial marker E-cadherin, were observed in both lentivirus infected SCLC and NSCLC cells overexpressing the stemness marker CD44v6. Aneuploid CTCs and CTECs expressing CD44v6 were longitudinally detected by SE-iFISH in 120 SCLC patients. Positive detection of baseline CD44v6+ CTCs and CD44v6+ CTECs was significantly associated with enhanced hepatic metastasis. Karyotype analysis revealed that chromosome 8 (Chr8) in CD44v6+ CTCs shifted from trisomy 8 towards multiploidy in post-therapeutic patients compared to pre-treatment subjects. Furthermore, the burden of baseline CD44v6+ CTCs (t0) or amid the therapy (t1-2), the ratio of baseline CD31+ CTEC/CD31- CTC (t0), and CTC-WBC clusters (t0) were correlated with treatment response and distant metastases, particularly brain metastasis, in subjects with limited disease (LD-SCLC) but not in those with extensive disease (ED-SCLC). Multivariate survival analysis validated that longitudinally detected CD44v6+/CD31- CTCs was an independent prognostic factor for inferior survival in SCLC patients. Our study provides evidence for the first time that comprehensive analyses of CTCs, CTECs, and their respective CD44v6+ subtypes enable clinical stratification and improve prognostic prediction of SCLC, particularly for potentially curable LD-SCLC.

Targeting immune cell types of tumor microenvironment to overcome resistance to PD-1/PD-L1 blockade in lung cancer

Lung cancer is the common malignant tumor with the highest mortality rate. Lung cancer patients have achieved benefits from immunotherapy, including immune checkpoint inhibitors (ICIs) therapy. Unfortunately, cancer patients acquire adaptive immune resistance, leading to poor prognosis. Tumor microenvironment (TME) has been demonstrated to play a critical role in participating in acquired adaptive immune resistance. TME is associated with molecular heterogeneity of immunotherapy efficacy in lung cancer. In this article, we discuss how immune cell types of TME are correlated with immunotherapy in lung cancer. Moreover, we describe the efficacy of immunotherapy in driven gene mutations in lung cancer, including KRAS, TP53, EGFR, ALK, ROS1, KEAP1, ZFHX3, PTCH1, PAK7, UBE3A, TNF-α, NOTCH, LRP1B, FBXW7, and STK11. We also emphasize that modulation of immune cell types of TME could be a promising strategy for improving adaptive immune resistance in lung cancer.