CMTM6 attenuates cisplatin-induced cell death in OSCC by regulating AKT/c-Myc-driven ribosome biogenesis.

CMTM6, a type 3 transmembrane protein, is known to stabilize the expression of programmed cell death ligand 1 (PD-L1) and hence facilitates the immune evasion of tumor cells. Recently, we demonstrated that CMTM6 is a major driver of cisplatin resistance in oral squamous cell carcinomas (OSCC). However, the detailed mechanism of how CMTM6 rewires cisplatin resistance in OSCC is yet to be explored. RNA sequencing analysis of cisplatin-resistant OSCC lines stably expressing Nt shRNA and CMTM6 shRNA revealed that CMTM6 might be a potential regulator of the ribosome biogenesis network. Knocking down CMTM6 significantly inhibited transcription of 47S precursor rRNA and hindered the nucleolar structure, indicating reduced ribosome biogenesis. When CMTM6 was ectopically over-expressed in CMTM6KD cells, almost all ribosomal machinery components were rescued. Mechanistically, CMTM6 induced the expression of C-Myc, which promotes RNA polymerase I mediated rDNA transcription. In addition to this, CMTM6 was also found to regulate the AKT-mTORC1-dependent ribosome biogenesis and protein synthesis in cisplatin-resistant lines. The nude mice and zebrafish xenograft experiments indicate that blocking ribosome synthesis either by genetic inhibitor (CMTM6KD) or pharmacological inhibitor (CX-5461) significantly restores cisplatin-mediated cell death in chemoresistant OSCC. Overall, our study suggests that CMTM6 is a major regulator of the ribosome biogenesis network and targeting the ribosome biogenesis network is a viable target to overcome chemoresistance in OSCC. The novel combination of CX-5461 and cisplatin deserves further clinical investigation in advanced OSCC.

RRBP1 rewires cisplatin resistance in oral squamous cell carcinoma by regulating Hippo pathway.

BACKGROUND: Chemoresistance is one of the major factors for treatment failure in OSCC. Identifying key resistance triggering molecules will be useful strategy for developing novel treatment methods. METHODS: To identify the causative factors of chemoresistance, we performed RNA sequencing and global proteomic profiling of human OSCC lines presenting with sensitive, early and late cisplatin-resistance patterns. RESULTS: From the common set of dysregulated genes from both the analysis, RRBP1 was identified to be upregulated in both early and late cisplatin-resistant cells with respect to the sensitive counterpart. Analysis of OSCC patient sample indicates that RRBP1 expression is upregulated in chemotherapy-non-responder tumours as compared to chemotherapy-responder tumours. Genetic (knockout) or pharmacological (Radezolid, represses expression of RRBP1) inhibition of RRBP1 restores cisplatin-mediated cell death in chemo-resistant OSCC. Mechanistically, RRBP1 regulates Yes-associated protein1 (YAP1), a key protein in the Hippo pathway to induce chemoresistance. The PDC xenograft data suggests that knockout of RRBP1 induces cisplatin-mediated cell death and facilitates a significant reduction of tumour burden. CONCLUSION: Overall, our data suggests that (I) RRBP1 is a major driver of cisplatin-resistance in OSCC, (II) RRBP1 regulates YAP1 expression to mediate cisplatin-resistance, (III) Radezolid represses RRBP1 expression and (IV) targeting RRBP1 reverses cisplatin-induced chemoresistance in advanced OSCC.

DDX3 modulates cisplatin resistance in OSCC through ALKBH5-mediated m6A-demethylation of FOXM1 and NANOG.

Platinum based drugs alone or in combination with 5FU and docetaxel are common regimen chemotherapeutics for the treatment of advanced OSCC. Chemoresistance is one of the major factors of treatment failure in OSCC. Human RNA helicase DDX3 plays an important role in cell proliferation, invasion, and metastasis in several neoplasms. The potential role of DDX3 in chemoresistance is yet to be explored. Enhanced cancer stem cells (CSCs) population significantly contributes to chemoresistance and recurrence. A recent study showed that m6A RNA regulates self-renewal and tumorigenesis property in cancer. In this study we found genetic (shRNA) or pharmacological (ketorolac salt) inhibition of DDX3 reduced CSC population by suppressing the expression of FOXM1 and NANOG. We also found that m6A demethylase ALKBH5 is directly regulated by DDX3 which leads to decreased m6A methylation in FOXM1 and NANOG nascent transcript that contribute to chemoresistance. Here, we found DDX3 expression was upregulated in both cisplatin-resistant OSCC lines and chemoresistant tumors when compared with their respective sensitive counterparts. In a patient-derived cell xenograft model of chemoresistant OSCC, ketorolac salt restores cisplatin-mediated cell death and facilitates a significant reduction of tumor burdens. Our work uncovers a critical function of DDX3 and provides a new role in m6 demethylation of RNA. A combination regimen of ketorolac salt with cisplatin deserves further clinical investigation in advanced OSCC.

STAT3- and GSK3ß-mediated Mcl-1 regulation modulates TPF resistance in oral squamous cell carcinoma.

Cisplatin alone or in combination with 5FU (5-fluorouracil) and docetaxel (TPF) are common regimen chemotherapeutics for treatment of advanced oral squamous cell carcinoma (OSCC). Despite the initial positive response, several patients experience relapse due to chemoresistance. The potential role of Bcl-2 antiapoptotic members in acquired chemoresistance is yet to be explored. To address this, we designed two different relevant OSCC chemoresistant models: (i) acquired chemoresistant cells, where OSCC lines were treated with conventional chemotherapy for a prolonged period to develop chemoresistance, and (ii) chemoresistant patient-derived cells, where primary cells were established from tumor of neoadjuvant-treated OSCC patients who do not respond to TPF. Among all Bcl-2 antiapoptotic members, Mcl-1 expression (but not Bcl-2 or Bcl-xL) was found to be upregulated in both chemoresistant OSCC lines and chemoresistant tumors when compared with their respective sensitive counterparts. Irrespective of all three chemotherapy drugs, Mcl-1 expression was elevated in OSCC cells that are resistant to either cisplatin or 5FU or docetaxel. In chemoresistant OSCC, Mcl-1 mRNA was upregulated by signal transducer and activator of transcription 3 (STAT3) activation, and the protein was stabilized by AKT-mediated glycogen synthase kinase 3 beta (GSK3ß) inactivation. Genetic (siRNA) or pharmacological (Triptolide, a transcriptional repressor of Mcl-1) inhibition of Mcl-1 induces drug-mediated cell death in chemoresistant OSCC. In patient-derived xenograft model of advanced stage and chemoresistant OSCC tumor, Triptolide restores cisplatin-mediated cell death and facilitates significant reduction of tumor burdens. Overall, our data suggest Mcl-1 dependency of chemoresistant OSCC. A combination regimen of Mcl-1 inhibitor with conventional chemotherapy deserves further clinical investigation in advanced OSCC.

Role of Cyclin-Dependent Kinase 4/6 in Metastatic Breast Cancer: Real-World Data From a Tertiary Care Institute in Eastern India.

Introduction CDK4/6 inhibitors currently approved for patients with hormone-receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer include palbociclib, ribociclib, and abemaciclib. This study aims to report on the treatment outcomes and real-world data regarding the use of CDK4/6 inhibitors in the treatment of ER+/HER2- metastatic breast cancer at a tertiary care institute in Eastern India. Materials and methods The present study is a retrospective analysis of data from patients with metastatic HR+/HER2- breast cancer who were treated with CDK4/6 inhibitors at a tertiary care institute in Eastern India between 2015 and 2022. The data were collected from online records in the departmental files and analyzed for the primary baseline characteristics of the patients, tumors, and response rates, including partial response (PR), complete response (CR), progressive disease (PD), and stable disease (SD), as defined by the Response Evaluation Criteria in Solid Tumors (RECIST) criteria version 1.1. The treatment administered, progression-free survival (PFS), and toxicity were also evaluated. Results From 2015 to 2022, 24 eligible patients were treated with CDK4/6 inhibitors for metastatic HR+/HER2- breast cancer. The average duration of follow-up was 25 months. Out of the 24 patients, 15 (62.5%) were taking Tab. ribociclib, six (25%) were taking Tab. palbociclib, and three (12.5%) were taking Tab. abemaciclib. CDK4/6 was used as a first-line therapy for 16 patients, while eight patients received it as a second-line treatment. Out of the total number of patients, six (25%) had stable disease, 13 (54.2%) had a partial response, and four (16.7%) had progressive disease. In total, of the eligible patients, five (20.8%) had grade I neutropenia, seven (29.2%) had grade II neutropenia, and four (16.7%) had grade III neutropenia. At five years, the PFS rate estimated by the Kaplan-Meier method was 50% (95% CI: 47.89-69.31). Conclusion Ribociclib and palbociclib have improved PFS in patients with metastatic HR+/HER2- breast cancer. Both drugs have well-tolerated toxicity, allowing patients to continue taking them for an extended period of time. CDK4/6 inhibitors have a higher response rate than the other agents.

PD-L1 Expression in Colorectal Carcinoma Correlates with the Immune Microenvironment.

INTRODUCTION/BACKGROUND: Colorectal carcinoma (CRC) is a common malignancy, with its diverse clinical, pathological, and molecular features. The immune microenvironment of a tumor comprises of interplay between various cells and molecules, and has a significant role in deciding the tumor behavior and overall prognosis. PD-L1 (programmed cell death ligand-1) has been implicated in the regulation of the tumor immune microenvironment (TIME). There is limited data regarding the correlation of PD-L1 expression with immune cell profile in CRCs, especially in the Indian setting. The study aimed to assess the PD-L1 expression in CRC tumor cells and its association with TIME, mismatch repair (MMR), and various other clinicopathological parameters. METHODS: This is a hospital-based, cross-sectional observational study. PD-L1 expression was assessed at the protein level by immunohistochemistry and mRNA level by qRT-PCR. Immune cell markers (CD4, CD8, CD20, FOXP3, and CD163) were interpreted using the ImageJ Fiji platform. RESULTS: Of the 104 cases, 21% were PD-L1 positive and were more common in right-sided CRCs. PD-L1 positive cases showed significantly higher concentrations of all T-cell subsets (CD4+ , CD8+ , and FOXP3+), CD20+ B-cells, and CD163+ macrophages were noted. No statistical significance was seen between PD-L1 expression with clinical profile, pathological subtype, grade or stage, mismatch repair status (proficient vs deficient), and survival. CONCLUSIONS: The present study showed a relatively lower frequency of PD-L1 in CRC from the Eastern Indian cohort. The immune cell concentration in the present study was calculated using image analysis-based objectivised methods. Significant correlation of PD-L1 expression in tumor cells with the tumor-infiltrating immune cells indicated its crucial role in the pathobiology of CRC especially by regulating the TIME. Considering the therapeutic implication of PD-L1 in various malignancies, it may be one of the crucial therapeutic targets in a proportion of cases.

A comparative study in left-sided breast cancer treated with moderate deep inspiratory breath hold versus free breathing.

BACKGROUND: The moderate deep inspiratory breath hold (mDIBH) is a modality famed for cardiac sparing. Prospective studies based on this are few from the eastern part of the world and India. We intend to compare the dosimetry between mDIBH and free-breathing (FB) plans. METHODS: Thirty-two locally advanced left breast cancer patients were taken up for the study. All patients received a dose of 50 Gy in 25 fractions to the chest wall/intact breast, followed by a 10-Gy boost to the lumpectomy cavity in the case of breast conservation surgery. All the patients were treated in mDIBH using active breath coordinator (ABC). The data from the two dose volume histograms were compared regarding plan quality and the doses received by the organs at risk. Paired t-test was used for data analysis. RESULTS: The dose received by the heart in terms of V5, V10, and V30 (4.55% vs 8.39%) and mean dose (4.73 Gy vs 6.74 Gy) were statistically significant in the ABC group than that in the FB group (all p-values < 0.001). Also, the dose received by the LADA in terms of V30 (19.32% vs 24.87%) and mean dose (32.99 Gy vs 46.65 Gy) were significantly less in the ABC group. The mean treatment time for the ABC group was 20 min, while that for the free-breathing group was 10 min. CONCLUSIONS: Incorporating ABC-mDIBH for left-sided breast cancer radiotherapy significantly reduces the doses received by the heart, LADA, and left and right lung, with no compromise in plan quality but with an increase in treatment time.

A rare case of cavernous sinus thrombosis following oral squamous cell carcinoma - The etiology and management dilemma.

Intracranial cavernous sinus metastases of oral squamous cell carcinoma (OSCC) are rare, with a reported incidence of 0.4 %. Due to their extremely infrequent presentation the etiology and management modalities of such complications are not clearly represented in the literature. Here we present a case of a 58-year-old male diagnosed with OSCC of Right Lower Alveolus with underlying bone invasion, cT4aN1M0, Stage IV. He underwent Right Hemi-mandibulectomy with Modified Neck Dissection, Pectoralis Major Myocutaneous Flap, and 60 Gy/30# adjuvant radiotherapy. Six months later, the patient was diagnosed with recurrence involving the right infratemporal fossa with associated right cavernous sinus thrombosis. Immunohistochemistry block review showed PDL1 - Positive. The patient was subjected to Cisplatin and Pembrolizumab immunotherapy. After receiving 35 cycles of Pembrolizumab over a period of 2 years the patient is doing well with no recurrence.

Cutaneous Metastasis in a Treated Case of Cervical Cancer With Extraordinary Response to Chemotherapy: A Case Report of a Rare Event and Review of the Literature.

Cervical cancer usually metastasizes to the lung, liver, bone, and brain. Metastasis to the skin from cervical cancer is relatively uncommon. The management options are systemic therapy, palliative radiotherapy, or best supportive care. Here, we report the case of a female patient with cervical cancer, stage IIB, who received radical treatment with radiotherapy and chemotherapy and later presented with disseminated skin nodules. She was treated with combination chemotherapy (nano-dispersible paclitaxel and carboplatin), bevacizumab, and a bone-stabilizing agent (zoledronic acid). There was a complete metabolic response to the therapy. There was also a dramatic improvement in the general condition of the patient. Skin metastasis in cervical cancer often presents as non-tender skin nodules. A biopsy is mandatory to establish the diagnosis. There are no specific guidelines about management. The intention of management is palliative. The combination of chemotherapy and bevacizumab produces substantial clinical improvement.

Mono iso-centric VMAT planning for SBRT of multiple liver metastasis- A case report.

INTRODUCTION: Hepatocellular carcinoma (HCC) is the second most common cause of cancer mortality worldwide. The risk factors associated with the development of HCC are chronic Hepatitis B, Hepatitis C, and alcoholic cirrhosis. The standard care for HCC is surgical resection but the scope is limited for some patients. Continuous advancement of radiation therapy enabled the technique of stereotactic body radiotherapy (SBRT) as an option for the treatment of those cases for which surgery cannot be done. According to recent literature and meta-analysis, SBRT is an optimum treatment method with high local control with low toxicity. In SBRT, radiation is delivered with a smaller number of fractions than conventional radiation and employs high-precision delivery and accuracy with the help of image guidance. From a series of retrospective and prospective studies, it has been confirmed that SBRT achieves excellent local control in patients with early-stage inoperable, intermediate-stage, and advanced diseases. BACKGROUND: A 42-year-old male patient related to HBeAg infection and high AFP levels developed HCC BCLC Stage A was admitted to our department. There were two lesions with PTV volumes of 41.07 cc and 9.573 cc with a distance between them of 3.51 cm. These two lesions were treated with a mono-isocentric VMAT planning with SBRT technique. In this case, we present an unusual clinical practice of mono-isocentric treatment planning for treating multiple liver lesions. Since radiation therapy was viewed as the primary form of treatment because the patient wasn't an ideal candidate for surgery, SBRT was selected as the patient's primary modality of treatment because of the tiny volume of the two lesions and the normal liver volume (>700cc). Triple-phase 4DCT was performed for simulation to account for the motion of target volume and normal structures. After delineating the target volume and other normal structures, treatment planning was done with a dose of 45 Gray which was to be delivered in 5 fractions. Two PTVs were created with a margin of 3.0 mm to IGTV. Considering the positions of the lesions, a single isocentre plan was created using a 6MV FFF photon beam for both the PTVs with the VMAT technique. The treatment was carried through with 3 arcs, one coplanar, and the other 2 non-coplanar. At the time of treatment, after the proper positioning of the patient, one CBCT image was taken to match with the planned CT image acquired at the time of the simulation. After applying the translational and rotational errors, the patient was treated. RESULTS: The patient was treated successfully. After treatment, the condition of the patient was normal, and no toxicities have been observed in follow-up. CONCLUSION: Mono isocentric VMAT planning can be used for closely spaced lesions considering the position of lesions and other normal structures in the vicinity.

Metastatic Renal Cell Carcinoma Masquerading as a Laryngeal Tumor: A Case Report.

Renal cell carcinoma (RCC) commonly metastasizes to various organs such as the lungs, liver, bones, and brain. However, isolated metastases to the head and neck region, especially the larynx, are very rare. This report presents a case of laryngeal growth that was eventually confirmed to be a metastatic deposit from an undiagnosed RCC. We report a case of a 66-year-old male who presented to the clinic with painless neck swelling and a change in voice. The scan showed a soft tissue mass in the thyroid cartilage. Histopathology of the resected laryngeal tumor confirmed metastatic clear cell carcinoma. A metastatic workup revealed a renal mass, and the patient underwent laparoscopic adrenal-sparing left cytoreductive nephrectomy. The histopathological examination established the diagnosis of clear cell RCC. Subsequently, the patient was treated with pembrolizumab and lenvatinib. Follow-up imaging showed no residual or recurrent lesions. This case highlights the rarity of laryngeal metastasis from RCC and the importance of an accurate diagnosis through advanced imaging and histopathological examination.

Inclusion of Perineural Invasion with AJCC-TNM Staging: Outcomes from a South Asian Cohort of Curatively Treated Gastric Cancer Patients.

BACKGROUND: The incidence of perineural invasion (PNI) in patients with gastric cancer (GC) is high, and patients with PNI positive disease have a poor prognosis compared to PNI-negative disease. The present study aims to study the incidence and evaluate the impact of PNI on the survival outcome of a cohort of South Asian GC patients. MATERIAL AND METHODS: All consecutive patients undergoing curative gastrectomy were included in the study. The incidence of PNI and correlation with different clinico-pathological features and overall survival was performed. RESULTS: A total of 59.54% had PNI-positive disease and the median OS of PNI + ve patients was 29.3 months, while it was not reached in PNI-ve patients. The PNI positivity was a significant prognostic factor for overall survival both on univariate and multivariate analysis. On TNM-PNI staging, those with TNM stage I/II patients with PNI + ve disease had similar OS to all stage III patients (p = 0.835) and were worse than that of PNI-ve patients (p < 0.05). CONCLUSION: The incidence of PNI in gastric cancer is high. The inclusion of PNI with AJCC-TNM staging may better stratify prognostic staging in curatively treated gastric cancer patients.

Inguinal lymph node metastasis in treated breast cancer: an extremely rare presentation and review of literature.

Metastasis to inguinal lymph nodes from breast cancer is extremely rare and only a handful of cases have been reported in the literature to date. We report a case of a postmenopausal female patient who was a treated case of right breast cancer and developed inguinal metastases after 9 months. An excisional biopsy of the lesion confirmed the diagnosis. A positron emission tomography-CT scan revealed retropectoral and pelvic lymphadenopathy. The patient was treated with palliative radiotherapy to the inguinal and pelvic regions followed by palliative chemotherapy. The patient survived for 4 months after the detection of inguinal metastasis.

Metastatic primary gastric melanoma: a rare clinical presentation and a review of literature.

Primary gastric melanoma is a rare clinical finding. It presents with upper gastrointestinal symptoms like abdominal pain, weight loss and melaena. It is often difficult to differentiate a primary gastric melanoma from primary cutaneous melanoma with gastric metastasis. Upper gastrointestinal endoscopy and biopsy of the lesion for histopathology and immunohistochemistry help to reach a definite diagnosis. We report a case of primary gastric melanoma with metastases to the liver and bone. The patient was treated with palliative radiotherapy, palliative chemotherapy and a bone-stabilising agent.

How prepared the radiotherapy centers are to deal with COVID-19 pandemic? A nationwide survey from 46 cancer centers across India.

Managing of radiotherapy department in many cancer centers in India has become very challenging during the COVID-19 pandemic. A radiotherapy center has to deal with multiple problems such as long treatment duration of each patient, high caseload on each radiotherapy machine, a limited number of qualified technical staff available, and equipment maintenance. For the department's smooth running, both the patient and healthcare worker must be safe from contacting COVID-19. A robust and planned strategy is required for prevention, screening, and awareness among all. To access our preparedness and evolve by gaining from other radiotherapy centers, a study was conducted using questionnaires and responses collected from different cancer centers in India.

Effect of treatment interruptions and outcomes in cancer patients undergoing radiotherapy during the first wave of COVID-19 pandemic in a tertiary care institute.

INTRODUCTION: COVID-19 patients with cancer had poorer outcomes due to immunosuppression during cancer care, poor general condition, and other comorbidities. The study was conducted to present the real-world analysis of the effect of treatment interruptions on the outcomes of patients treated with radiation therapy during the first wave of the COVID-19 pandemic in a tertiary care institute in India. MATERIALS AND METHODS: The study is a retrospective observational cohort study on cancer patients undergoing radiation therapy from March 2020 to January 2021. The study's primary outcome was to analyze the effect of treatment interruptions on the outcomes of patients treated with radiation therapy during the first wave of COVID-19 pandemic. RESULTS: Between March 2020 to January 2021, 218 eligible patients undergoing radiation therapy were found for the study. Among the 218 patients, 25 patients (11.47%) were found positive for COVID-19, while 193 patients (88.53%) were negative for COVID-19. Among COVID-19-positive patients, ten patients had < 3 weeks of treatment interruption, while 15 patients had > 3 weeks of treatment interruptions. After recovering from COVID-19, treatment was resumed and completed for 15 (60.00%) of the COVID-19-positive patients. In comparison, 13 patients (52.00%) were lost to follow-up. Three of the COVID-19-positive patients died. The disease was clinically controlled in 12 (48.00%) of the COVID-19-positive patients, and the patients reported locoregional disease progression in 10 (40.00%). Among the 193 COVID-19-negative patients, 32 patients (16.58%) had treatment interruption. Twelve patients (37.50%) had treatment interruptions for less than 1 week. There was a significant difference in the delay of radiation treatment delivery by 2 weeks (11 fractions) in COVID-19-positive patients compared to only two fractions delay in COVID-19-negative patients. CONCLUSION: COVID-19 impacted the treatment outcomes in both COVID-19-positive and COVID-19-negative cohorts of patients. There was a longer duration of treatment interruptions in the COVID-19-positive patients, leading to fewer patients completing the radiation treatment and thereby increased locoregional disease progression. There was a significant difference in the delay in treatment between the two groups.

Chemotherapy-induced hand foot syndrome: comparative efficacy and safety of pharmacological prophylaxis - systematic review and Bayesian network meta-analysis.

BACKGROUND: Hand-foot syndrome (HFS) is one of the most common toxicities experienced by patients receiving systemic chemotherapy agents such as capecitabine and multikinase inhibitors such as sorafenib. Several randomised controlled trials (RCTs) have investigated the efficacy and safety of prophylactic agents such as pyridoxine, celecoxib, urea cream and cystine/theanine in managing HFS. This network meta-analysis (NMA) evaluated data from high-quality trials to provide strong evidence in forming recommendations to prevent systemic cancer therapy-induced HFS. OBJECTIVE: To examine the comparative efficacy and safety of interventions for preventing systemic chemotherapy-induced HFS in patients with cancer. METHODS: We searched PubMed, Embase and clinical trial registry for RCTs of interventions for preventing HFS. Bayesian NMA was performed to estimate the OR with 95% credible intervals (CrI) from both direct and indirect evidence. The outcome measures were the incidence of HFS (grade ≥1) and moderate to severe HFS (grade ≥2). Adverse drug reactions were discussed descriptively. RESULTS: A total of 15 RCTs with 2715 patients with 12 prophylactic strategies were included. The analysis showed only celecoxib could significantly prevent the incidence of moderate to severe HFS (grade ≥2) (OR 0.29, 95% CrI 0.13 to 0.68). But none of the preventive interventions could prevent the incidence of HFS (grade ≥1). CONCLUSION: Only celecoxib (200 mg two times per day) showed significant prevention of the incidence of moderate to severe HFS. Pyridoxine (400 mg once daily) and urea cream (10%) have to be evaluated further in larger randomised trials.

Divided target optimization with volumetric modulated arc therapy planning to improve target coverage and homogeneity in lung radiation therapy.

PURPOSE: To investigate and evaluate the feasibility of a simple modified Divided Planning Target Volume (DPTV) optimization method in radiation therapy planning of lung cancer patients. METHODS: A cohort of 15 patients of Non-Small Cell Lung Cancer (13 patients stage III and two patients of stage II) who were previously treated with Concurrent Chemo Radiation Therapy were included in the study. The planning modality was Volumetric Modulated Arc Therapy, and the dose prescription was 60 Gray in 30 fractions. In this study, we attempted to replan by dividing the previous Single Planning Target Volume (SPTV) into a DPTV. All the treatment plans were revised and again optimized for DPTV with required dose constraints as in SPTV. The dosimetric parameters that were achieved for target and normal structures were recorded in both the optimization methods. RESULTS: Dosimetric target coverage (D95%) (p-value = 0.0001), dose homogeneity (p-value =0.0001) and conformity (p-value = 0.044) were improved by the DPTV optimization. The volume of the oesophagus receiving 35 Gy was found to be higher in the DPTV arm (p-value = 0.02) compared to the SPTV arm, but the volume of the oesophagus receiving 50 Gy was found to be similar (p-value = 0.122). CONCLUSION: In radiation therapy planning of lung cancer, the DPTV optimization method has better dose coverage to the target volume, homogeneity, as well as conformity than the stsndsrd SPTV method. Therefore, the DPTV optimization method can be a simple and efficient alternative to the SPTV method in lung cancer.

CRISPR-based kinome-screening revealed MINK1 as a druggable player to rewire 5FU-resistance in OSCC through AKT/MDM2/p53 axis.

Cisplatin, 5FU and docetaxel (TPF) are the most common chemotherapy regimen used for advanced OSCC. However, many cancer patients experience relapse, continued tumor growth, and spread due to drug resistance, which leads to treatment failure and metastatic disease. Here, using a CRISPR/Cas9 based kinome knockout screening, Misshapen-like kinase 1 (MINK1) is identified as an important mediator of 5FU resistance in OSCC. Analysis of clinical samples demonstrated significantly higher MINK1 expression in the tumor tissues of chemotherapy non-responders as compared to chemotherapy responders. The nude mice and zebrafish xenograft experiments indicate that knocking out MINK1 restores 5FU mediated cell death in chemoresistant OSCC. An antibody based phosphorylation array screen revealed MINK1 as a negative regulator of p53. Mechanistically, MINK1 modulates AKT phosphorylation at Ser473, which enables p-MDM2 (Ser 166) mediated degradation of p53. We also identified lestaurtinib as a potent inhibitor of MINK1 kinase activity. The patient derived TPF resistant cell based xenograft data suggest that lestaurtinib restores 5FU sensitivity and facilitates a significant reduction of tumor burden. Overall, our study suggests that MINK1 is a major driver of 5FU resistance in OSCC. The novel combination of MINK1 inhibitor lestaurtinib and 5FU needs further clinical investigation in advanced OSCC.